interactive exercises, online calculators and plotters, mathematical recreation and games

Keywords: interactive mathematics, interactive math, server side interactivity

wimshomeabcd 4.28Documents Other languages: fresitnlcasidecn

- Université Côte d’Azur
- Université Paris-Saclay
- Università di Milano--Bicocca
- Caen University
- Institut Baix Penedès. El Vendrell
- Università di Chieti-Pescara
- Université de Savoie
- Universitat Rovira i Virgili. Tarragona

WIMS Home Site: http://wims.unice.fr/ Source codes

Function calculator, for one-variable real functions: limits, integrals, roots...

Shifting puzzle, recover a jigsaw puzzle by shifting rows or columns.

Matrix calculator, computes determinant, inverse, eigenvectors,...

Linear solver, solves linear systems, including systems with parameters.

Matrix multiplier, input two matrices and get their product (or other formula).

Animated drawing, plot zooming, deforming and rotating curves and surfaces.

Factoris, factors integers and polynomials.

Base converter, converts a number between different numbering systems, arbitrary precision.

Vector calculator, linear dependence, orthogonal complement, visualisation, products...

Primes, searching for primes in different ways.

Bar game, simple step game, play against the server.

Wcalc, multi-purpose single-step calculator usable in popup mode.

Graphic functions, recognize the graph of f(-x) from that of f(x), etc.

Decrypt, recover a crypted text.

Numerical calculator, numerical calculator with modifiable history; real/complex or positive characteristics.

Graphic derivative, recognize the graph of the derivative of a function.

Bezout, computes euclidean division, gcd, lcm, Bezout relation.

OEF Fractions, collection of exercises on fractions.

Coincidence-Polynomial, find a polynomial according to its curve.

Polyray, visualize implicit algebraic surfaces by ray tracing.

Gravity shoot, click on the gravity center of a given configuration.

Visual Gauss, step by step Gauss elimination (for matrix or system).

Rotation shoot, click on the center of a rotation 2D.

Arithmetic tables, arithmetic training exercise-game with highly variable levels.

Complex shoot, locate a complex number by clicking on the complex plane.

Elliptic billiards, bouncing on a billiard table of elliptic form.

Goldbach, write an even integer as sum of two primes.

Quizz derivative, elementary questions on derivatives.

Triangular shoot, click on one of the centers of a triangle.

Magic rectangles, game based on a variation of magic squares.

Contfrac, expand a real number into continued fraction.

Line choice, exercise : recognize a line by equation or by graph.

Sigma, computes sums of series or finite sums of various kinds.

OEF Rectangles, collection of exercises on rectangles.

Graphic inverse, recognize the graph of an inverse function.

Sequence plot, plot a numerical sequence or series.

OEF proportionality, collection of exercises on proportionality.

Additive figures, place numbers in geometric figures according to conditions on sums.

Quizz Matrices, elementary questions on matrices.

OEF Matrices, collection of exercises on matrices.

Recognize a map and its properties, visual exercise on the definition of a map.

OEF Complex numbers, collection of exercises on complex numbers.

Derivative draw, given the graph of a function, draw that of the derivative.

OEF Linsys 2x2, collection of exercises on elementary linear systems 2x2.

Quadratic choice, recognize the graph of a quadratic polynomial.

OEF Clock, collection of exercises on clock recognition.

Homothety shoot, click on the center of an homothety 2D.

Bases, find a basis of a vector subspace under various definitions.

Graphic complex inequalities, recognize a region of the complex plane described by inequalities.

Vector shoot, click on a linear combination of 2D vectors.

Choice of ellipses, recognize an ellipse according to its equation, or vice versa.

Pathfind, link points by a shortest path.

Animated sequences, animated plot of a sequence (series) of functions.

Quizz complex, elementary questions on complex numbers.

Basis choice, find a basis of a vector subspace within given vectors.

Graphic addition, recognize the graph of f(x)+g(x) from that of f and g, etc.

Wfind, find words by letter patterns.

Interactive integration, solve an integration step by step.

Cross multiplication, find a matrix not commuting with a given one.

Coincidence sinus, find a sinusoidal function according to its graph.

OEF Periodic table, exercises for memorising the periodic table of elements.

Tangent 2D, find tangent / normal line of a plane curve.

Coincidence Freehand, find the best possible approximation of a given curve.

Circular draw, draw the circumscribed circle (cinscribed circle , circumcircle, incircle) of a triangle.

Parmsys, analyse a linear system with parameters, using Gauss elimination.

Parametric points, plots a parametric curve with moving point.

Graphic subsets, recognize a graphically described subset.

OEF inverse, collection of exercises on the inverse function of a real bijective function.

Graphic integral, recognize the graph of the integral of a function.

Partial equation, fill-in an equation to make it correct, drag-and-drop style exercises.

Inverse draw, draw an inverse function.

Function draw, draw a function using the graph of another.

Segfrac, split a fraction into sum of fractions with smaller denominators.

Popup calculator forms, you can search calculating forms or insert them into your own web pages.

Morse Training, code/decode a text in Morse code.

Quizz integration, elementary questions on integration.

Two squares, decompose an integer into sums of two squares.

Taylor, algebraic manipulations of Taylor expansions.

Accordance, find a polynomial according to its values.

Epsilon, on the definition of continuity: given epsilon, find delta.

Vision 4D, plots hypersurfaces etc. in space-time of dimension 4.

Linear system dialog, ask questions to get information in order to solve linear systems.

Order arrangement, arrange given numbers according to their order.

OEF derivative, practising with differentiation.

OEF Triangles, collection of exercises on triangles.

Linear shoot, click on the image of a point by a linear transformation.

SQRT shoot, locate (square, cubic, ...) roots of a complex number by clicking on the complex plane.

OEF Modular arithmetic, collection of exercises on the ring Z/nZ.

MVT calc, a computing exercise on Mean Value Theorem.

OEF Determinant, collection of exercises on the determinant of a square matrix.

Basis change, write a vector under another basis.

OEF subspace definition, collection of exercices on the definition of subspace of vector spaces.

Complex equation draw, draw an equation in the complex plane.

Primitive draw, given the graph of a function, draw that of an anti-derivative.

Min-Max, exercises on minima / maxima.

Rank filler, complete a matrix for a minimal rank.

Tangent parameters, find the curve having a given tangent.

Graphic ODE, graphically recognize solution of a linear ordinary differential equation.

Polynomial sweep, Graphs and roots of a polynomial, with animated deformation.

PermGroup, calculator of permutation groups based on GAP: symmetric, alternating, transitive, primitive, etc.

Derivative dialog, ask questions to get information in order to compute derivatives.

OEF gcd, collection of exercises on gcd and lcm of integers.

Coincidence-Dev, graphically find the Taylor expansion of a function.

OEF Linear systems, collection of exercises on linear systems.

Parametric choice, from a parametric curve, recognize values or derivatives of functions. Animated graphics.

Genspace, does a given set of vectors generate the whole vector space?.

Parametric compose, recognize a parametric curve by the graphs of its coordinate functions.

Inequality zone, determine an inequality for variables in a given zone.

Equaffine, rewrite a line/plane/hyperplane: by points or by explicit/implicit/parametric equations.

Decomp, decompose a composed function.

Graphic inequalities 2D, recognize a plane region described by inequalities.

Joint, parametrize a function to make it differentiable to a required order.

Huffman, find an optimal encoding in variable length codes.

Finite field calculator, computes elements in a finite field.

Triangmult, find two triangular matrices whose product is a given square matrix.

Affine fixed, find the fixed point of an affine transformation.

Extend-subspace, extend a vector subspace to a required dimension.

OEF Ohm, exercises on ohm's law and serial and parallel connections.

MatEq, asks to solve matrix equations.

Quizz determinant, elementary questions on the determinant of a matrix.

Symmetric split, write a given matrix as sum of symmetric and antisymmetric matrices.

Transfinite arithmetic, transformation in Z/nZ by addition and multiplication.

Coinc_EqDif, graphical exercise about differential equations.

Coincidence Transformation, transform a given 2D shape into another given one.

Simu-bubble, manually simulate a bubble sort.

Graphical decrypt, decrypt a picture crypted by a psudo-random sequence.

Graphical convergence, determine the limit of a recursive sequence according to the graph of the function.

Coincidence Addition, find the linear combination of two functions by their graphs.

OEF Cartesian line 2D, collection of exercises on lines in the plane and their equations.

OEF vectors 2D, collection of exercises on 2D vectors.

Limited derivatives, find the bound of a function having bounded derivative.

Flatten, parametrize a function to make it infinitesimal at a point.

Scenario of inequalities, discover errors in an argument on inequalities.

Roottest, find the root of a function by successive tests.

OEF finite map, collection of exercises on maps between finite sets.

OEF proba, collection of exercises on elementary probability.

Polynomial order, computes the order of an irreducible polynomial over a finite field**F**_{p}.

Parametric draw, draw a parametric curve from graphs of coordinate functions, requires java.

Coincidence Polyroots, find a polynomial according to the positions of its roots.

Circuit draw, tool for drawing simple electronic circuit schematics.

Linear image, compute the image of a vector by a linear or affine map.

Graphic multiplication, recognize the graph of fg from that of f and g, etc.

Linsys find, establish a linear system according to a word problem.

OEF iff, collection of training exercises on necessary and sufficient conditions.

OEF defining interval, collection of exercises on the defining interval of a real function.

Lissajous choice, recognize a Lissajous curve according to its equations, or vice versa.

Fourier development, graphical search of Fourier development of a function.

SQRT draw, draw roots of a complex number.

Lintersect, find the intersection of 2 lines, 2 planes, line and plane, etc.

Deductio inequalities 0, exercises of interactive deduction on inequalities, basic deductions.

Graphic abs, recognize the graph of f(|x|) from that of f(x), etc.

Moving Comet Shoot, exercice demandant de trouver la position d'un soleil connaissant le mouvement d'un satellite (nécessite java).

Prime congruence base, find a prime for the base of a congruence relation.

Hamming complement, find a maximum of binary words respecting a given Hamming distance.

Coincidence Param, find the best approximation of a parametric curve.

Parafocus shooting, shoot at the focus in the picture of a parabola.

OEF Logic quantifiers, collection of exercises on logic quantifiers.

OEF RC/RL, exercises on the bahavior of RC/RL circuit under sinusoidal signals.

Parametric cusp, parametrize a parametric curve so that it has a cusp.

Rankmult, find two matrices whose product is a given matrix.

Primpoly, search for primitive polynomials over a finite field.

Ray 3D, generates raytraced smooth 3D surfaces from parametric equations.

Reflaxis, find the axis of a reflection given by matrix, or vice versa.

Prog string, programming exercises on string processing.

Graphic ODE phase graph, recognize the phase graph of a given ODE.

Correcode, decode a message containing errors by an error correcting code.

Coincidence sequence, find a sequence from partial informations and via successive tests.

Deductio linear system, exercises of interactive deduction on linear systems.

Inverse Huffman, find a distribution of probabilities so that a given code is optimal.

Varicode, find a code with given word lengths.

Prog sum of integers, programming exercises on summing a list of integers.

Deductio bounds, exercises of interactive deduction on (upper and lower) bounds of functions.

Joint II, parametrize a function to make it continue or differentiable on 2 points.

Introduction to Powers, practising with powers

Prog divisibility, programming exercises on the divisibility of integers.

H4 series and sequences, Starting with series and sequences

Prog modular arithmetics, programming exercises on modular arithmetics.

Counting, Adding and Multiplication

Trigonometry: determine the function, Use an applet to determine the correct arguments to a trigonometric function

Graph-Relation, given a piecewise linear graph y=f(x), determine the graph of f(x)=f(y).

Newton-Inverse, use Newton-Raphson algorithm to compute inverse value of a function and also the derivative of the inverse function

Parabolic trough calculator, determining the design parameters of small closed parabolic troughs.

Direct exec, direct access to most computing and graphing tools interfaced by WIMS.

Data General interest science topics, audio collection used in an exercise module.

Data Debating, audio collection used in an exercise module.

Special relativity and steps towards general relativity, elementary relativity exercises. ((c) GPL and/or CC-BY-SA-3.0 or later).

OEF Tenses and conditionals, exercises on present and past tenses, conditionals.

Suffixes and prefixes, collection of exercises on word formation with suffix and prefix.

Linkwords, exercises on linkwords for sequencing, contrast, cause, consequence.

English for economy and management (1), 3 articles, with a set of about 10 various exercises each (listening comprehension, vocabulary, preposition, passive voice...).

English for Economy and Management (02), 3 articles, with a set of about 10 different exercises each (listening comprehension, vocabulary, prepositions, passive voice...).

Doc Linkwords, document on linkwords.

Syntax of mathematical expressions, how to read, to write or to draw an expression.

OEF Limit calculus with logarithms or exponentials, practising with computational rules of limits and indeterminate forms.

Shifting puzzle, recover a jigsaw puzzle by shifting rows or columns.

Matrix calculator, computes determinant, inverse, eigenvectors,...

Linear solver, solves linear systems, including systems with parameters.

Matrix multiplier, input two matrices and get their product (or other formula).

Animated drawing, plot zooming, deforming and rotating curves and surfaces.

Factoris, factors integers and polynomials.

Base converter, converts a number between different numbering systems, arbitrary precision.

Vector calculator, linear dependence, orthogonal complement, visualisation, products...

Primes, searching for primes in different ways.

Bar game, simple step game, play against the server.

Wcalc, multi-purpose single-step calculator usable in popup mode.

Graphic functions, recognize the graph of f(-x) from that of f(x), etc.

Decrypt, recover a crypted text.

Numerical calculator, numerical calculator with modifiable history; real/complex or positive characteristics.

Graphic derivative, recognize the graph of the derivative of a function.

Bezout, computes euclidean division, gcd, lcm, Bezout relation.

OEF Fractions, collection of exercises on fractions.

Coincidence-Polynomial, find a polynomial according to its curve.

Polyray, visualize implicit algebraic surfaces by ray tracing.

Gravity shoot, click on the gravity center of a given configuration.

Visual Gauss, step by step Gauss elimination (for matrix or system).

Rotation shoot, click on the center of a rotation 2D.

Arithmetic tables, arithmetic training exercise-game with highly variable levels.

Complex shoot, locate a complex number by clicking on the complex plane.

Elliptic billiards, bouncing on a billiard table of elliptic form.

Goldbach, write an even integer as sum of two primes.

Quizz derivative, elementary questions on derivatives.

Triangular shoot, click on one of the centers of a triangle.

Magic rectangles, game based on a variation of magic squares.

Contfrac, expand a real number into continued fraction.

Line choice, exercise : recognize a line by equation or by graph.

Sigma, computes sums of series or finite sums of various kinds.

OEF Rectangles, collection of exercises on rectangles.

Graphic inverse, recognize the graph of an inverse function.

Sequence plot, plot a numerical sequence or series.

OEF proportionality, collection of exercises on proportionality.

Additive figures, place numbers in geometric figures according to conditions on sums.

Quizz Matrices, elementary questions on matrices.

OEF Matrices, collection of exercises on matrices.

Recognize a map and its properties, visual exercise on the definition of a map.

OEF Complex numbers, collection of exercises on complex numbers.

Derivative draw, given the graph of a function, draw that of the derivative.

OEF Linsys 2x2, collection of exercises on elementary linear systems 2x2.

Quadratic choice, recognize the graph of a quadratic polynomial.

OEF Clock, collection of exercises on clock recognition.

Homothety shoot, click on the center of an homothety 2D.

Bases, find a basis of a vector subspace under various definitions.

Graphic complex inequalities, recognize a region of the complex plane described by inequalities.

Vector shoot, click on a linear combination of 2D vectors.

Choice of ellipses, recognize an ellipse according to its equation, or vice versa.

Pathfind, link points by a shortest path.

Animated sequences, animated plot of a sequence (series) of functions.

Quizz complex, elementary questions on complex numbers.

Basis choice, find a basis of a vector subspace within given vectors.

Graphic addition, recognize the graph of f(x)+g(x) from that of f and g, etc.

Wfind, find words by letter patterns.

Interactive integration, solve an integration step by step.

Cross multiplication, find a matrix not commuting with a given one.

Coincidence sinus, find a sinusoidal function according to its graph.

OEF Periodic table, exercises for memorising the periodic table of elements.

Tangent 2D, find tangent / normal line of a plane curve.

Coincidence Freehand, find the best possible approximation of a given curve.

Circular draw, draw the circumscribed circle (cinscribed circle , circumcircle, incircle) of a triangle.

Parmsys, analyse a linear system with parameters, using Gauss elimination.

Parametric points, plots a parametric curve with moving point.

Graphic subsets, recognize a graphically described subset.

OEF inverse, collection of exercises on the inverse function of a real bijective function.

Graphic integral, recognize the graph of the integral of a function.

Partial equation, fill-in an equation to make it correct, drag-and-drop style exercises.

Inverse draw, draw an inverse function.

Function draw, draw a function using the graph of another.

Segfrac, split a fraction into sum of fractions with smaller denominators.

Popup calculator forms, you can search calculating forms or insert them into your own web pages.

Morse Training, code/decode a text in Morse code.

Quizz integration, elementary questions on integration.

Two squares, decompose an integer into sums of two squares.

Taylor, algebraic manipulations of Taylor expansions.

Accordance, find a polynomial according to its values.

Epsilon, on the definition of continuity: given epsilon, find delta.

Vision 4D, plots hypersurfaces etc. in space-time of dimension 4.

Linear system dialog, ask questions to get information in order to solve linear systems.

Order arrangement, arrange given numbers according to their order.

OEF derivative, practising with differentiation.

OEF Triangles, collection of exercises on triangles.

Linear shoot, click on the image of a point by a linear transformation.

SQRT shoot, locate (square, cubic, ...) roots of a complex number by clicking on the complex plane.

OEF Modular arithmetic, collection of exercises on the ring Z/nZ.

MVT calc, a computing exercise on Mean Value Theorem.

OEF Determinant, collection of exercises on the determinant of a square matrix.

Basis change, write a vector under another basis.

OEF subspace definition, collection of exercices on the definition of subspace of vector spaces.

Complex equation draw, draw an equation in the complex plane.

Primitive draw, given the graph of a function, draw that of an anti-derivative.

Min-Max, exercises on minima / maxima.

Rank filler, complete a matrix for a minimal rank.

Tangent parameters, find the curve having a given tangent.

Graphic ODE, graphically recognize solution of a linear ordinary differential equation.

Polynomial sweep, Graphs and roots of a polynomial, with animated deformation.

PermGroup, calculator of permutation groups based on GAP: symmetric, alternating, transitive, primitive, etc.

Derivative dialog, ask questions to get information in order to compute derivatives.

OEF gcd, collection of exercises on gcd and lcm of integers.

Coincidence-Dev, graphically find the Taylor expansion of a function.

OEF Linear systems, collection of exercises on linear systems.

Parametric choice, from a parametric curve, recognize values or derivatives of functions. Animated graphics.

Genspace, does a given set of vectors generate the whole vector space?.

Parametric compose, recognize a parametric curve by the graphs of its coordinate functions.

Inequality zone, determine an inequality for variables in a given zone.

Equaffine, rewrite a line/plane/hyperplane: by points or by explicit/implicit/parametric equations.

Decomp, decompose a composed function.

Graphic inequalities 2D, recognize a plane region described by inequalities.

Joint, parametrize a function to make it differentiable to a required order.

Huffman, find an optimal encoding in variable length codes.

Finite field calculator, computes elements in a finite field.

Triangmult, find two triangular matrices whose product is a given square matrix.

Affine fixed, find the fixed point of an affine transformation.

Extend-subspace, extend a vector subspace to a required dimension.

OEF Ohm, exercises on ohm's law and serial and parallel connections.

MatEq, asks to solve matrix equations.

Quizz determinant, elementary questions on the determinant of a matrix.

Symmetric split, write a given matrix as sum of symmetric and antisymmetric matrices.

Transfinite arithmetic, transformation in Z/nZ by addition and multiplication.

Coinc_EqDif, graphical exercise about differential equations.

Coincidence Transformation, transform a given 2D shape into another given one.

Simu-bubble, manually simulate a bubble sort.

Graphical decrypt, decrypt a picture crypted by a psudo-random sequence.

Graphical convergence, determine the limit of a recursive sequence according to the graph of the function.

Coincidence Addition, find the linear combination of two functions by their graphs.

OEF Cartesian line 2D, collection of exercises on lines in the plane and their equations.

OEF vectors 2D, collection of exercises on 2D vectors.

Limited derivatives, find the bound of a function having bounded derivative.

Flatten, parametrize a function to make it infinitesimal at a point.

Scenario of inequalities, discover errors in an argument on inequalities.

Roottest, find the root of a function by successive tests.

OEF finite map, collection of exercises on maps between finite sets.

OEF proba, collection of exercises on elementary probability.

Polynomial order, computes the order of an irreducible polynomial over a finite field

Parametric draw, draw a parametric curve from graphs of coordinate functions, requires java.

Coincidence Polyroots, find a polynomial according to the positions of its roots.

Circuit draw, tool for drawing simple electronic circuit schematics.

Linear image, compute the image of a vector by a linear or affine map.

Graphic multiplication, recognize the graph of fg from that of f and g, etc.

Linsys find, establish a linear system according to a word problem.

OEF iff, collection of training exercises on necessary and sufficient conditions.

OEF defining interval, collection of exercises on the defining interval of a real function.

Lissajous choice, recognize a Lissajous curve according to its equations, or vice versa.

Fourier development, graphical search of Fourier development of a function.

SQRT draw, draw roots of a complex number.

Lintersect, find the intersection of 2 lines, 2 planes, line and plane, etc.

Deductio inequalities 0, exercises of interactive deduction on inequalities, basic deductions.

Graphic abs, recognize the graph of f(|x|) from that of f(x), etc.

Moving Comet Shoot, exercice demandant de trouver la position d'un soleil connaissant le mouvement d'un satellite (nécessite java).

Prime congruence base, find a prime for the base of a congruence relation.

Hamming complement, find a maximum of binary words respecting a given Hamming distance.

Coincidence Param, find the best approximation of a parametric curve.

Parafocus shooting, shoot at the focus in the picture of a parabola.

OEF Logic quantifiers, collection of exercises on logic quantifiers.

OEF RC/RL, exercises on the bahavior of RC/RL circuit under sinusoidal signals.

Parametric cusp, parametrize a parametric curve so that it has a cusp.

Rankmult, find two matrices whose product is a given matrix.

Primpoly, search for primitive polynomials over a finite field.

Ray 3D, generates raytraced smooth 3D surfaces from parametric equations.

Reflaxis, find the axis of a reflection given by matrix, or vice versa.

Prog string, programming exercises on string processing.

Graphic ODE phase graph, recognize the phase graph of a given ODE.

Correcode, decode a message containing errors by an error correcting code.

Coincidence sequence, find a sequence from partial informations and via successive tests.

Deductio linear system, exercises of interactive deduction on linear systems.

Inverse Huffman, find a distribution of probabilities so that a given code is optimal.

Varicode, find a code with given word lengths.

Prog sum of integers, programming exercises on summing a list of integers.

Deductio bounds, exercises of interactive deduction on (upper and lower) bounds of functions.

Joint II, parametrize a function to make it continue or differentiable on 2 points.

Introduction to Powers, practising with powers

Prog divisibility, programming exercises on the divisibility of integers.

H4 series and sequences, Starting with series and sequences

Prog modular arithmetics, programming exercises on modular arithmetics.

Counting, Adding and Multiplication

Trigonometry: determine the function, Use an applet to determine the correct arguments to a trigonometric function

Graph-Relation, given a piecewise linear graph y=f(x), determine the graph of f(x)=f(y).

Newton-Inverse, use Newton-Raphson algorithm to compute inverse value of a function and also the derivative of the inverse function

Parabolic trough calculator, determining the design parameters of small closed parabolic troughs.

Direct exec, direct access to most computing and graphing tools interfaced by WIMS.

Data General interest science topics, audio collection used in an exercise module.

Data Debating, audio collection used in an exercise module.

Special relativity and steps towards general relativity, elementary relativity exercises. ((c) GPL and/or CC-BY-SA-3.0 or later).

OEF Tenses and conditionals, exercises on present and past tenses, conditionals.

Suffixes and prefixes, collection of exercises on word formation with suffix and prefix.

Linkwords, exercises on linkwords for sequencing, contrast, cause, consequence.

English for economy and management (1), 3 articles, with a set of about 10 various exercises each (listening comprehension, vocabulary, preposition, passive voice...).

English for Economy and Management (02), 3 articles, with a set of about 10 different exercises each (listening comprehension, vocabulary, prepositions, passive voice...).

Doc Linkwords, document on linkwords.

Syntax of mathematical expressions, how to read, to write or to draw an expression.

OEF Limit calculus with logarithms or exponentials, practising with computational rules of limits and indeterminate forms.

Please take note that WIMS pages are interactively generated; they are not ordinary HTML files. They must be used interactively ONLINE. It is useless for you to gather them through a robot program.