All Questions

96 views

How to show that an expression is 0 if FullSimplify never finishes

I have a huge expression. And I have "checked" numerically that it is 0 for real value variables. However, due to the size and structure of the expression FullSimplify seems to be having a hard time. ...
260 views

How to embed a filled Region in a Graphics?

Let for example: regn = RegionDifference[Rectangle[{-2, -2}, {2, 2}], Disk[{0, 0}, 1]]; The only documented way I found to draw a gereric region ...
290 views

Include more padding between tick marks and plot [duplicate]

How can I modify the code below to add some padding between my tick marks and 3D plot? It is not a problem in this example, but often my tick marks collide with my axes. ...
85 views

How to get an element of a list , which is computed out of substituted variables?

What is the best way to get the element of a list, which is computed out of substituded variables? For example one wants to get the first element of the first row of ...
243 views

Another weird plotting result

I asked a question this morning here, which has been resolved. However, I got another problem. I want to add some lines to the graph, which turns out glitched. The code is as follows, ...
289 views

How to get a multiple line plot from a list of lists

Following this data input {{{2,4,6,8,9},{342432,435345,564564,56756,9945},{23,356,565,304,564},{3,67,76,44,7}}} The array is the data of three lines. The first ...
165 views

Passing function as argument

I've been mucking around with passing functions as arguments to other functions and via trial and error seem to have something that works. I was wondering if someone could have a quick look at some ...
276 views

Question2:: ...
184 views

Error when attempting to save Notebook. Cause and solution?

I am experiencing an error attempting to save a modified Notebook in Mathematica 10 under Windows. The error I get is: ...
381 views

NSolve for high degree univariate polynomials

I am trying to solve a high degree univariate polynomial using Mathematica's NSolve command. But when I plug the solutions generated by Mathematica back to the equations, the equations are massive ...
562 views

Create a matrix of matrices using Band and ArrayFlatten [duplicate]

I can easily write a simple Band matrix using: SparseArray[{Band[{2, 1}] -> a}, {Dim, Dim}] where a is a number. Now, I ...
186 views

Animation of moving rectangles in 2D from data file

I am not very familiar with mathematica but I know the basics so I thought I give it a try. For a project I have to animate rectangles moving around in 2D (later also 3D). The data come from a C ...
184 views

How can I remove edges from my DiscretePlot?

By default, DiscretePlot displays "edges" along the sides and, prominently, align the top when ExtentSize -> Full is set. For ...
200 views

Requiring NumericQ in Pure Function

Potential duplicate, but doesn't seem to solve my problem: Using patterns in pure functions I have a function that returns an InterpolatingFunction, and it works ...
76 views

How can I automatically name files being exported based on input parameters

I have Mathematica notebook that performs some operation say a=2 b=3 c=5 d=4 how do I set the output file after evaluation to be named using the values ...
455 views

Understanding the difference between matrix indices and image coordinates in context of ListDensityPlot

In Mathematica help it's written that: ListDensityPlot[array] -> generates a smooth density plot from an array of values. ...
373 views

Generating complete lists of polynomials

I would like to generate a list of all $3$-variable Laurent polynomials with non-negative integer coefficients using a looping construct so that I can, one-by-one, check them for specific ...
510 views

Prove (or check) an expression is positive given constraints on variables?

I'm trying to figure out whether an expression is always positive given positive parameters. When the expression is complicated, I can't do this by eye. Is there any way to make Mathematica prove ...
1k views

Get positions of all non zero matrix elements

I want to find all non zero elements of a table and I want to create a list that contains the name of the table the element was removed from, the position of the element, and the value of the element. ...
258 views

Order of symbols in Graphics labels

Do you have any idea how to force an order of Greek letter in the graphics? When I type in AxesLabel -> {Cost, Δ OverBar[π]} the order is π Δ. How can I ...
187 views

Join matrix based on conditions

Given the following matrix: ...
441 views

Typesetting - entering derivative in traditional form

I am trying to work out how I enter a differential in standard notation? I am familiar with using D, but everything I have tried to enter a differential has failed. ...
2k views

Plot3D region bounded by equations?

I have four equations, $$z = xy \\ z=0 \\ y=x^2 \\ x=y^2$$ I would like to integrate the region bounded by them. Before this, I would like to plot the region they bound, but I cannot seem to find ...
182 views

Show contour area as tooltip?

I have contour plots, such as plot = ContourPlot[Sqrt[(x - 2)^2 + (y - 2)^2 - 5], {x, -15, 15}, {y, -15, 15}, Contours -> {4}] /. _Polygon -> Sequence[] I ...
181 views

Using DeleteCases with multiple AstronomicalData properties

I am attempting to use AstronomicalData and DeleteCases together to remove invalid cases of two properties while listing the ...
1k views

Fourier Series of “Split” Defined Function

Not sure how to phrase this in a concise way, anyway it seems like the function FourierSeries assumes the interval for which to compute the Fourier coefficients of a given function is $[-\pi,\pi]$, ...
193 views

How to exclude numbers in a series and still plot the graph? [duplicate]

I want to plot this: $\displaystyle\sum_{n=-{10}\atop n\ne \pm 1}^{10} \dfrac {4i(-1)^{n}n}{(n^2 - 1)^2}e^{inx}$ but have no idea how I can exclude the cases for when $n = \pm 1$. I don't wish to ...
448 views

Calculate scalar potential from electric field

Is it possible for Mathematica to solve an equation like $\nabla f(\mathbf{r}) = - \mathbf{E}(\mathbf{r})$ for $f(\mathbf{r})$? I tried ...
490 views

FrameLabel and OverTilde

What is the problem with this expression inside ListPrint? OverTilde generates here a mess: ...
763 views

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303 views

Lossless TIFF or PNG export

I'd like to export an output from MatrixPlot[], however, the output file size seems to depend on my specification of the ImageSize -> {..., ...}. How might I export a TIFF with all of the data in the ...
265 views

Unresolved differential equation [closed]

Why can't Mathematica solve this equation as stated? ...
754 views

Making a ListVectorPlot3D from data in an external file

I have a .dat file with six columns: {x y z vx vy vz}, where x, y, z are space coordinates and vx, vy, vz are the vector components. How can I use this file to get ...
303 views

Exporting HTML code to file.html

I've got a problem with re-saving html code. Lets create html file: ...
2k views

NDSolve: methods and step size choosing

I am looking into the documentation of NDSolve[]; more precisely how this function chooses the StepSize and how it chooses which ...
128 views

Can you form a list with elements which are terms from an equation?

Is there a command that takes an equation as an input and creates an output with a list of terms in the original equation? Something like: ...
320 views

Is it possible to treat starting values as variables?

I have a problem where I am using FindRoot a gazillion times over a grid of parameters. I need to allow the starting values to vary a bit with the parameters to get it to converge. Here is a simple ...
139 views

The proper way to write the input for a certain series

Mathematica tells the series below doesn't converge. I think it converges. What would the proper way to write things be as an input? ...
737 views

How to guess initial complex value for FindRoot

I have to solve a transcendental equation for a parameter, say $\beta$. Now, the $\beta$ has a range from $ik$ to $k$ where $i$ is the usual imaginary root $\sqrt{-1}$ and $k$ is a real number. ...
1k views

NDSolve two PDE plus one ODE, together

I have a couple of PDE (time and space/length) that are correctly managed by NDSolve, but to which I’m adding an ODE on which the acc “accumulates”, through time, a ...
4k views

Plotting a large number of data points

I would like to know how to plot when I have a large number of points (arround 600) in a specific format: ...
202 views

How to change the Integer to a special form in an expression?

I have an expression. I want to change all the Integers to a new form. The rule is, x_Integer->x._f. But we should consider some special cases. For example, ...
120 views

Graphing the amount of time a function takes

I know I can find out the amount of time a function takes to run like this: In:= function1[100] //Timing Out:= {0.043334, Null} How can I graph this over a set ...
81 views

How do I eliminate the breaks in a 3D plot with a Max or Min function? [duplicate]

Whenever I make a 3D plot using the Max or Min functions, I get breaks in the plot when it switches from one expression in ...
661 views

Packages problems on version 9 under OS X

Using Version 9 on OS X, I've run into some problems with creating packages and accessing them. I've done the following: wrote all the function definitions in a notebook and tested that they all ...
660 views

How to format a large Number

There is a large number a = 123456789012345678901234567.123456789012345678901234567 By format with AccountingForm ...
148 views

Total elements of a list that have a common first element [duplicate]

Possible Duplicate: List-operations only when restrictions are fulfilled (Part 1) I have a set of data like: ...
289 views

Plot, HoldAll and the color problem

I have a similar problem as posted in Difference in Plot when using Evaluate vs when not using Evaluate, however due to a numerical evaluation I cannot use ...
I want to make a list of chemical reactions and I write them down in a $\require{mhchem}\LaTeX$ format. They are of the following form NA_n^i+MB_m^j \rightarrow \hat NA_{\hat n}^{\hat i}+\hat ...