For help with mathematical questions arising from software such as Maple, MATLAB, Mathcad, Pari/GP, R, and the WolframAlpha website, etc. Consider posting questions about Mathematica at the Mathematica StackExchange instead. For GAP, SAGE, and MAGMA, one might use tags (computer-algebra-systems), (...

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2answers
46 views

Find non-diagonal matrices $A$ and $B$ such that $B^TAB$ is diagonal

Here $B^T$ denotes the transpose of $B$. $A$ and $B$ are invertible $3\times 3$ matrices with integer entries. $A$ is symmetric positive definite with at most two zero entries. We want the ...
2
votes
1answer
26 views

Computing Smith Normal Form of $ \begin{pmatrix} 1 & c_{12} & c_{13} \\ 0 & 1 & c_{23} \\ 0 & 0 & 1 \\ \end{pmatrix}$

I think this is a simple question, I am looking for a program which computes the smith normal form or rational canonical form of a matrix. Not something fancy, I want just to compute the smith normal ...
0
votes
0answers
49 views

software for the general integer solutions of quadratic diophantine equations

Does anyone know of software (either commercial or free/open) that implements the general algorithm to solve quadratic diophantine equations as shown in this paper by Grunewald and Segal (2004), ...
0
votes
0answers
25 views

How can I evaluate this integral in R program?

I want to evaluate $$f=\int_{0}^{\infty}\ldots \int_{0}^{\infty}x_1x_2\phi_n(\mathbf{x},\mathbf{\mu},\mathbf{\Sigma})\,dx_1\,dx_2\ldots \,dx_n,$$ where $\phi_n(\mathbf{x},\mathbf{\mu},\mathbf{\Sigma})...
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0answers
9 views

How to put constraint on the rank of a matrix to be completed using CVX toolbox [migrated]

I would like to complete a matrix using cvx toolbox in MATLAB. For example: ...
2
votes
0answers
26 views

Straightforward software for publication-quality geometrical sketches.

What is the simplest, most straightforward package for draw simple geometrical 2D sketches that involve circles, straight lines and vectors, for a professional mathematical Tex-made document? I am ...
0
votes
1answer
28 views

Sign of a Linear Expression in Mixed Integer Linear Programming

I have a question about a system in mixed integer programming I am trying to solve using GLPK though the question mathematical and is software agnostic. I have converted the whole problem to linear ...
-3
votes
2answers
66 views

Why do graphing calculators plot this function wrong? Wolfram Mathematica example.

Wrong graph of the function f(x)=-1^x The function in question is $f(x)=-1^x$ and the plot example is from Wolfram Mathematica. The graph is supposed to show a zig-zag otherwise known as the triangle ...
0
votes
1answer
28 views

How to get the coefficient of the constant part of a multivariate polynomial in MAGMA?

In the MAGMA software package, given a multivariate polynomial $f$ in some polynomial ring , how do we get its constant part? For univariate polynomials the method ConstantCoefficient(f) returns (...
1
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1answer
42 views

User directed prime testing for smallish integers (100-1000 decimal digits)

I have become interested recently in (A1) what one can do, if anything, about ~100 digit numbers with no easy factors and no access to anything but basic calculators/software that can cope with ...
2
votes
0answers
26 views

Software for solving first-order logic

Is there any class of software that can help me with the following problem in first order logic: given $\phi$ a formula with a "hole" in it (a subformula which is undetermined) and a particular set of ...
3
votes
1answer
56 views

Is there a searchable database of mathematical objects that you can search by property?

For example, I could search for functions that are continuous, but that don't have differentiability, and come up with a continuous non-differentiable function. Or a smooth but non-analytical function....
1
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0answers
10 views

Is there a tool which converts an algebraic expression from Latex to Maxima? [closed]

I have written an algebraic expression in Latex as it looks much easier to understand than if I would have made it directly in wxMaxima. Is there is any way now to import that expreesion to wxMaxima ...
0
votes
1answer
25 views

Automatic tools for solving a set of inequalities

I am trying to solve problems such as the following: Find real numbers $a_1,a_2,a_3, b_1,b_2,b_3$ such that all following expressions are true: $a_1+a_2+a_3=0$ $b_1+b_2+b_3=0$ $a_1>...
1
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2answers
58 views

Polynomial Regression for Images instead of Data Points

My goal is to calculate the time of evaporation for water when this vase (below) is completely full. I understand that the simplest way would be to experimentally measure the evaporation time, however,...
0
votes
1answer
61 views

Theoretically, can mathematical equations be used to graph any picture imaginable? [duplicate]

I know that quadratic formulas make parabolas, linear makes straight lines and sin, cos and tan make cool curves but after messing around with WolframAlpha and online equation graphing tools I can ...
211
votes
15answers
15k views

Math without pencil and paper

For someone who is physically unable to use a pencil and paper, what would be the best way to do math? In my case, I have only a little movement im my fingers. I can move a computer mouse and press ...
2
votes
1answer
18 views

Matlab - set like datatype?

I'm need to work with Matlab again but it's long ago that I did so the last time. So I need your help (searching for "set" leads only to how to set colors of axis and so...). How can I achieve a set ...
0
votes
2answers
51 views

Working with C++ for GF(2) [closed]

Pardon me if it is off topic.But, is there anyone who could suggest me some basics with how to get started with working with C++ for GF(2)?? I am new in C++.I am learning to working with arrays and ...
3
votes
1answer
35 views

Recommend of English video about math

My mother tongue is not English, but sometime there are some math reports or conference using English .Because my English is poor, I can't understand it well and can't suitably describe my question. ...
0
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0answers
14 views

SQP with non linear constraints

I am asked to solve a $SQP$ problem using Matlab, in the instructions for writing the code I am supposed to create two functions one for the function $f$ to minimize and one for the constraints $c_i$, ...
0
votes
0answers
16 views

Using optim and fitdistr in R to find parameters

I am using R to fit distributions. I have been given the data and have been asked to find the optimised parameters(for lognormal, weibull, exponential and gamma functions) using: 1) fitdistr and 2) ...
2
votes
1answer
73 views

Free programs to draw graphs?

allow me to draw graphs, lines, curves such as parabolas, set intervals with sliding bars etc. I have tried geogebra but it is very limited and is a pain to use. For example, you cannot set a line to ...
0
votes
1answer
42 views

Integration in Maple 16

I need to solve this integral in Maple 16, I've tried various functions such as evalf, solve, ...
1
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1answer
39 views

Study of specific Quotients of a $p$-group in MAGMA

In Magma, I wanted to do a program, but since I was getting errors in "basic" commands, I am in trouble. Here I will describe a problem to be done in MAGMA, then its interpretation in MAGMA. I would ...
0
votes
3answers
40 views

Explanation of sums

How would you explain this notation in plain English? I am having issues getting my head around the meaning of the summation symbol. $$ x = \frac1n\sum_{i=1}^n x_i\;. $$
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votes
2answers
46 views

How to load Maple package ??

I have downloaded second version of DGApplications to work with abstract Lie algebra. The file is actually .mla file and it is executale(as when we open it, a prompt ask, "do you want to execute this ...
0
votes
0answers
27 views

Software of symbolic computation

In Riemann geometry, there are many complex compute , for example in the picture below.If want to get 2.5.16 it needs about 3 page to compute. And it is easy to mistake because it is complex. But the ...
-1
votes
1answer
22 views

A Basic Question E-views

I ask a question about E-views. Is the P-value in the picture less than 0.05 or greater than 0.05? I'm confused because of the presence of the sign '<' in front of 0.10. Please help mee. Thank you.
0
votes
0answers
30 views

Finding best fit curve via 2nd order polynomial

I've set of data points and I need to best fit curve by using $y = a + bx + cx^2$. I know the method of finding $a,b$ and $c$. After getting $a,b,c$; How to use that equation to determine the points ...
0
votes
1answer
63 views

Using IEEE floating point standard in math-software. [closed]

For purposes of given math module (that performs some statistical computations) it's sufficient to store reals in IEEE754 floating point format. I'm considering to migrate to SQLLite as persistent ...
0
votes
0answers
33 views

Curve of all points C for which $|AC|=|BC|$ and $BC \parallel g$ …?

sorry for the title being a little bit weird. The full question is: Let's take two non parallel lines $g$ and $h$ and a fixed(!) point $A \not \in g$. Now take a look at all triangles $ABC$ for which:...
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0answers
21 views

Hirota's Bilinear Form

My query is related to conversion of PDE into bilinear form using some transformation. The detailed description about bilinear forms can be seen in book of Yoshimasa Matsuno . The bilinear operator ...
3
votes
2answers
66 views

math software - permutation group elements operation

I need a software allows to calculate operation elements of permutation group. For example the following elements operation yields identity permutation $$ (1234)(1423) = (1)$$ Sage seems to solve the ...
0
votes
1answer
71 views

Compute Ext with Macaulay2

I want to compute Ext with Macaulay2. I see in the website they write how to do but I can not do. Can anyone help me with an example? For example, let $S=k[x,y,z,t]$. How compute $\mathrm{Ext}^i_S (...
0
votes
0answers
185 views

Adding grid on 3D surface in GeoGebra 5

I have made a file with GeoGebra where I visualize a conical intersection. The standard appearance of the surfaces is a dull, colored surface, like shown in the attached figure. To better get a sense ...
0
votes
1answer
18 views

Computing difficult Fourier series numerically - software recommendation

I need to compute some pretty complex Fourier series of function like this one: $$ f(t) = \quad \begin{cases} 1+e^{-t}, & t\in [0;1)\\ 2, & t \in [1;3) \end{cases} $$ Rewritten to "one-line ...
0
votes
1answer
32 views

My brain doesn't work right now: What's the formula for the $n$th vertex of a discretized sine wave?

So far I have: $$ A \sin(2\pi f ? + \phi) $$ where $f$ is cycles per second, and $\phi$ is in seconds. If I'd like to approximate the sine wave with $N$ points per cycle, and I want to draw $C$ ...
5
votes
0answers
60 views

Are algorithms for elimination of quantifiers over the reals practical?

I wanted to find the semialgebraic set in the $(a_0,a_1,a_2,a_3)$ space that guarantees that there exists at least one real root of the general polynomial equation of degree 4. For that purpose, ...
0
votes
0answers
29 views

No graph shown on Microsoft Mathematics

When I try to graph this formula, $$y=\sum^x_{n=1}[n*\sum^n_{m=1}\sin(\frac{m}{n})]$$, the graph shows nothing. I thought it is possible that I input it in wrongly or the software can't solve this ...
1
vote
1answer
45 views

Is there a good program to download or online for plotting certain functions in 3d?

I am interested in a program that can plot me, without too much trouble shapes in 3d, when I type in the function. For example a elliptical paraboloid and an ellipse of the same time, so I can analyze ...
5
votes
1answer
117 views

Amount of zero in a range

I'm stuck with a calculation. If a person would write down, Everytime he sees a zero and counts +1. 10 counts as 1 zero. 100 counts as 2 zeros. 1000 has 3 zeros. 1005 counts as 2 zeros. Is there ...
0
votes
1answer
24 views

What is wrong with this code (SCILAB)?

i wrote this on scilab: function q=arrow(x0,y0,z0,a0,r,s) j=1; ...
0
votes
1answer
12 views

Given a line segment from $A$ to $B$, and a scale of your view of space $sx, sy$, how do you preserve width of line?

So I'm using PyQt5 to do 2D rendering for an LED light show creator app. The light shows are graphs where the $Y$-axis is LED brightness level and the $X$-axis is usually time. I have a zoom feature ...
1
vote
1answer
25 views

Graph a function of two variables online, with the output rendered as color

Are there any online utilities to graph a function of two variables online, with the output rendered as color in some way (for example, red to green, black to white, hue, etc...) Wolfram Alpha comes ...
1
vote
1answer
28 views

Program to create graph with modified bessel function

$$e =\frac{1}{x}\frac{I_{1}(2x)}{I_{0}(2x)}$$ $$e =\frac{2}{1+\sqrt{1+x²\frac{8}{3}}}$$ $$e =\frac{1}{\sqrt{x\frac{4}{3}}} \frac{I_{\frac{2}{3}}(x\frac{4}{3}^{3/2})}{I_{\frac{-1}{3}}(x\frac{4}{3}^{3/2}...
0
votes
0answers
21 views

Solve the cubic function (using graphing software)

Let $$f(x) = 2x - x^2$$ and $$g(x) = ax^3 + bx^2 + cx + d$$ where $a , b , c , d$ belong to the set of real numbers, and intersect at two points $P$ & $Q$. These points are also two points of ...
2
votes
2answers
91 views

Is there a site to draw a curve and get the equivalent equation?

I know there are many sites where we can input the equation and get the curve of the function (examples here, here and here). What I want is the inverse: I have an idea of how I want the curve to be, ...
0
votes
0answers
76 views

Running time comparison of algorithms

Which math software or programming language one should use in order to compare run times of two number theoretic algorithms ? I use PARI/GP but I am not sure if this is a right choice .
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1answer
33 views

Can you graph these kinds of equations with any free programs?

http://www.walkingrandomly.com/?p=19 I've been trying to find a way to graph this function without buying Mathematica but I haven't found a way. It might be possible with the free online Wolfram ...