1
vote
1answer
87 views

Issues with creating functions [duplicate]

Sometimes when I try to create a function inside a function, Mathematica gives me a hard time. I usually just have to play around with the syntax until it gets something it "likes" but I really have ...
9
votes
1answer
273 views

Mathematica: computing a difficult integral

I am trying to compute the following integral: Integrate[Exp[Sum[-((cw λ - b[i])^2/(2 σ^2)), {i, 1, n}]], {cw, 0, 1}] And currently Mathematica outputs ...
0
votes
2answers
206 views

Random variates in Recurrence Function

I'm completely new to Mathematica and can't seem to find an answer elsewhere so hopefully I can get some help here. I'm trying to plot a recurrence relation, where a random variate is generated at ...
12
votes
3answers
2k views

How to place legend labels for Histogram and ListLinePlots correctly?

I would like to place AxesLabels: For x axis at center of the Histogram and LineListPLots. For y axis rotated 90 degree anti clockwise. I don't see any options for it? ...
4
votes
1answer
76 views

Evaluate open cell segments in a notebook

The Evaluate > EvaluateNotebook evaluates the whole notebook. Is it possible to somehow evaluate ONLY the open sections of a notebook?
4
votes
1answer
176 views

Is it possible to interact with an external program's command-line interface?

I am performing a calculation in Mathematica which relies on calls to an external program that acts as a black box for calculating a function $f$, and I would like to know if it is possible for ...
26
votes
2answers
5k views

3D heatmap density plot

I have a set of data that looks like {{x1, y1, z1}, {x2, y2, z2}, ...} so it describes points in 3D space. I want to make a heatmap out of this data. So that points ...
1
vote
2answers
381 views

Coloring vertices using GraphPlot

I have the following problem: I used GraphPlot to plot my adjacency matrix. I divided my nodes in three groups: ...
1
vote
1answer
306 views

Row-Reduced-Echelon-Form with Equation Parameters for Consistent Systems

I often do row-reduced-echelon-form (RREF) calculations that involve parameters using the RowReduce command. Most times, I want to know which parameters make the system consistent. For example: ...
3
votes
4answers
106 views

Check whether a function of two variables is a probabilty distribution function

I have a function like this $f(x,y)=c\,y\,(y-x),\ \text{for}\ 0<x<2,\;-x<y<x$ and I need to find the value of $c$ such that $f(x,y)$ is a PDF. How can I do that? I know that the ...
4
votes
4answers
157 views

How to get a list of pairs into the form $(x,y)$?

I want to put the solutions of the equation $y = (x + 3)/(x - 3)$, where $x$, $y$ are integers, into the form $(x,y)$. For example, $(2, -5)$ instead of $\{2,-5\}$. When I evaluated ...
0
votes
1answer
101 views

Workaround for automatic replacement of “\r” to “\n”

When I run the following code in an empty notebook SetOptions[EvaluationNotebook[], testOption -> "\n\r"] and then open the notebook in Notepad, I find ...
2
votes
4answers
325 views

find the number of integral solutions a+b+c+d+e+f = 18 [duplicate]

Find the number of integral solutions of a + b + c + d + e + f = 18 where a, b, c, d, e, f are elements of the range ...
2
votes
1answer
143 views

How to embed graphic-element-specific metadata within a Graphics object?

One of the most crucial requirements for rich, interactive scientific graphics is being able to "annotate" individual graphic elements (e.g. the data points of a scatterplot, the individual curves in ...
4
votes
2answers
298 views

Find the value of parameter so that the equation has one solution

Let $(E_l) : x^4-4x^3+x^2(5-l^2)+4 x l^2-4l^2 = 0$ be an equation with $l$ as a parameter and $x$ as an unknown and $S_l$ the set containing all the real solutions of $(E_l)$. Then there is a unique ...
0
votes
2answers
226 views

Plotting problem

I was wondering why I keep receiving the error message "Derivative should be a triple of numbers, or scaled form" from the following code ...
5
votes
1answer
115 views

PearsonChiSquareTest: set degrees of freedom

How to set degrees of freedom for PearsonChiSquareTest? I have this: ...
3
votes
1answer
227 views
0
votes
0answers
11 views

Part::partd error on one of two similar lists [duplicate]

I have run into a problem that I can't explain. Here is the code: ...
5
votes
2answers
175 views

ParallelMap and Sow/Reap - not behaving as expected? [duplicate]

Is ParallelMap and Parallelize@Map expected to work with Sow and Reap construct. This is a rather brief toy code to find all Primes just to force the use of Sow/Reap inside Map ...
3
votes
0answers
55 views

Can I define a “postfix map” operator with comparable precedence behavior to // [duplicate]

I am trying to define a "postfix map" operator (denoted $OP$ for now) that behaves thus: ...
5
votes
2answers
173 views

How to optimize computing a product?

Problem description Write a function to caculate the formula My solutions Solution 1: ...
5
votes
1answer
156 views

Drawing a quadrangular surface

Is there a way to draw a quadrangular surface in Mathematica so that it shows the bilinear term (not two triangles)? The quadrangular polygon is given by the expression $$\phi = \sum_i^4 N_i U_i$$ ...
4
votes
4answers
129 views

Expanding lists with split strings

I've got data of the type: list = {"Class","MW","10 - 11"} which I would like to split into a number of lists based on the number of characters in the second ...
5
votes
0answers
143 views

How to deal with WebServices error “any is not supported in sequence”?

I am trying to aquire data through Mathematica's WebServices and this example works just fine: ...
4
votes
2answers
159 views

Adapting CoefficientList (and the related functions) to work with Laurent polynomials

Is there a slick way to make CoefficientList (and the other similar functions, CoefficientRules etc) work for Laurent polynomials (i.e. where negative exponents can occur), if I don't know a priori ...
4
votes
1answer
325 views

How to define a button inside Manipulate that tells Mathematica to re-evaluate the whole Manipulate code?

I have written a Manipulate code carrying out some very complicated tasks. There is no problem for the first run, but if I click the reset button to reset all ...
-2
votes
1answer
38 views

a basic question about getting the value of a parameter [closed]

i am new with Mathematica. i am trying to write a simple code. for example: phiu = 2 Yfu = (phi_u/(phi_u + 17.18)) but when i run it, it gives me (phi_u/(phi_u ...
0
votes
1answer
79 views

Evaluate outer function first

I'm new in Mathematica so this is maybe super easy to do, but I can't figure out how. I've got a function plus[a,b] that sums two numbers and I need to implement a ...
3
votes
1answer
289 views
4
votes
4answers
163 views

How can I make controls have Button-like behaviour?

The Button control is very easy to understand Button["Press Me", Print["Pressed"]] I press the button, I execute the ...
0
votes
1answer
93 views

Testing Equality Expression?

Even if in Graph[{1 -> 2}] == Graph[{1 \[DirectedEdge] 2}] the answer is True ; but why MMA doesn't show the result of the ...
5
votes
1answer
164 views

Looking to create a lesson on sensory perception of sound

I'm looking to show students a lesson on sensory perception, more specifically on masking. I know a little Mathematica but sound processing has evaded me. I would like to create a white noise and ...
1
vote
3answers
164 views
8
votes
1answer
161 views

FindSelectedFunction for packages - how to make it work?

The Mathematica help menu contains an entry Find Selected Function (Cmd+Shift+F on OSX). If you are working with say Transpose and want to look up its reference ...
2
votes
1answer
103 views

Input[] inside DynamicModule causing a kernel crash

I have those few lines of code causing a crash and I can't figure out why: ...
7
votes
1answer
162 views

RandomVariate does not fill range of PDF of distribution

I've declared my own probability distribution as follows dist[a_, b_] := ProbabilityDistribution[Cos[(b x)/2]^2 Sinc[a x]^2, {x, -400, 400}]; When I try to ...
2
votes
0answers
108 views

Equation Solving: Solution in terms of predefined functions

Is there a way that I can have Mathematica give me the solution of a problem it has solved in terms of functions that I have predefined? The specific problem I'm trying to solve is: ...
2
votes
2answers
313 views

Recursive formula involving a piecewise function

I am trying to construct a recursion, g[t], where g[t] = a[t] if g[t-1] = 1 ...
6
votes
1answer
679 views

Fastest way to do vector / matrix multiplication with constant matrix

Suppose we have a fixed n x n matrix, call it $B$. What is fastest way to evaluate $v^t B\;v$ over many different vectors $v$? Since $B$ is a constant matrix, does this allow the number of operations ...
0
votes
1answer
121 views

Efficiency problem with least square algorithm (Error in both variables)

I was informing myself about the least square algorithms with errors in x and y. I found this post and the top answer wasn't ...
2
votes
1answer
331 views

Avoiding zero (empty set) solution with NDSolve

I'm trying to use NDSolve for a chemical kinetics equation where the rate of conversion is given by this relationship as typed in Mathematica: ...
6
votes
4answers
1k views

How can I manipulate the number of decimal places in the frame ticks?

Is there any simple way to increase or decrease the decimal places in the frame ticks. I want to make the y axis ticks of the first two and the second two graphs look similar.
4
votes
0answers
108 views

MathKernel with `-noprompt` hangs indefinitely when converting simple TeX expression

If I enter MathKernel -noprompt -run 'ToExpression["1", TeXForm]; Exit[]' the kernel hangs, apparently while running TeX.exe ...
5
votes
2answers
131 views

How can AbsoluteTimes be split by date faster?

I have data where the date is stored as an AbsoluteTime. Here's a dummy dataset: ...
0
votes
0answers
34 views

Solving an algebraic equation with one or more constraints? [duplicate]

Just as a simple example, say I wanted to solve Sin[x] == a for x with the constraints -1<=a<=1 and 0 < x < Pi. Is there any way to do this?
0
votes
0answers
78 views

How to improve the quality of 3D rendering? [duplicate]

I am trying to combine various 3D objects for a composite image. But some of the objects just don't look very good. In the end, I want to have a publication-quality image. For example, here I ...
5
votes
1answer
244 views
3
votes
1answer
116 views

Dynamically apply a function fed by Input[]

Here is a bit of code: funlist = {Plot,ListPlot}; Input[Panel[PopupMenu[Dynamic@whichfun, funlist], "blabla"],Dynamic@whichfun] The idea here is to select what ...

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