All Questions

0
votes
0answers
19 views

Problem in Plot at start

The derivative can be used to calculate roots. However the same function cannot be plotted.The error is at start point of domain: ...
2
votes
1answer
13 views

Mapping also for one element (or telling it how to do so if head got changed)

Some code generates a polynomial, and has the form: expr = Plus[a[i],b[i],c[i],d[i]] I need to apply f to each term. To do ...
0
votes
0answers
13 views

Handling Accuracy and Simplifying

I have the following problem. I have a system of non-linear equations that I log-linearize around a certain point, let's call it point A, using a function that I ...
3
votes
1answer
26 views

Functional defined Ticks of LogLinearPlot does not work

version 10 $Version "10.0 for Microsoft Windows (64-bit) (June 29, 2014)" Consider three cases in LogLinearPlot's ...
3
votes
1answer
56 views

Is there an easy way to use Matteo Niccoli's perceptual color maps for 2D plots in Mathematica?

I have been using the ubiquitous Jet color palette for 2D plots for some time now, and don't really care for it. Then I came across the series of blog posts, The rainbow is dead...long live the ...
2
votes
1answer
30 views

Remove redundant parameters from equation

I have random expressions of the form (b1 x + b2 x)/(b3 + b4/b5 x) + Sin[b6 x] where $x$ is a variable and {b1, ..., b6} are parameters to be fitted. This ...
0
votes
0answers
23 views

Is There a Reliable Way to Solve the Following Non-linear PDE Using Mathematica?

I'm trying to solve the following non-linear PDE using Mathematica. Indeed I should write my own codes, but I didn't do it for two reasons: 1. there seems not to be any reliable way to "discretize" a ...
1
vote
1answer
42 views

handling division by zeros and line equations

today I was writing a code which takes some line equation and a circle equation,finds intersection points that are on $II$ and $III$ quadrants,draw a tangent line to circle from that point and then ...
0
votes
0answers
45 views

Mathematica ERROR [on hold]

I would like to know what your opinion is about this paper and the discovered errors: http://www.ams.org/notices/201410/rnoti-p1249.pdf I also like mathematica, but nevertheless a statement of ...
1
vote
1answer
20 views

problem on returning value of function as a list using if

today i was writing a function for my project using mathematica that gives a line equation in form of $y=mx+b$ and a circle equation in form of $x^2+y^2=r^2$ and finds the intersection point which is ...
0
votes
0answers
19 views

`EvaluationCompletionOption` -> `ShowTiming` broken in V10?

I've always had the Notebook Options > Evaluation Options > EvaluationCompletionOption set ...
0
votes
0answers
28 views

Empty Graph for Absolute Function

I wanted to plot the following equation: Plot[((x/7)^2 Sqrt[(Abs[Abs[x] - 3]/(Abs[x] - 3))] + (y/ 3)^2 Sqrt[(Abs[y + 3 Sqrt[33]/7])/(y + 3 Sqrt[33]/7)] - 1) (Abs[x/2] - ((3 ...
0
votes
0answers
21 views

Series expansion of InterpolatingFunction obtained from NDSolve

I am trying to obtain a series expansion of the numerical solution of a differential equation. I encounter difficulties going beyond first-order expansions which I believe might be due to my inability ...
0
votes
1answer
45 views

Partitioning time series

I have a time series dataset I'm trying to plot by Year: ...
0
votes
1answer
34 views

Why don't these assumptions result in further simplification?

I'm trying to simplify an expression, which has a factor of $\lambda(\lambda-1)$, where $\lambda$ may be either $1$, or $0$. So I try: ...
0
votes
1answer
26 views

Why can't I import a file in the init.m file?

I would like to have some data read in every time the kernel starts, but it doesn't seem to work. Say I have a CSV file I want to have read in, for example I use: ...
4
votes
1answer
64 views

How do I display the parameter value in animate, similar to how it's done in manipulate?

When I use manipulate, there is a 'plus sign' in the top right that, if I click on, shows my parameter value. I used animate, because other posts suggested that it solved other issues I had, but now ...
9
votes
0answers
79 views

DumpsterDoofus's captivating generative art

How can I render these beautiful images that DumpsterDoofus posted?
1
vote
1answer
43 views

Changing the Ticks in LogLinearPlot for representation pH values

I need to change the ticks in the xaxis for representation pH values, but the ticks are not dispersed along the range of xaxis. Another question: why the vertical line defined with Epilog is not ...
0
votes
0answers
10 views

Changing variable value via loop [on hold]

Just a quick question, I have the following code: Do[{ Mtest = 2; Mtest = Mtest + 0.1; Print[Mtest] }, {n, 1, 5}] What I hope to do is have it loop 5 ...
2
votes
1answer
33 views

Is there a simple function identify the sign of an expression given constraints

I'm looking to find a simple function that can identify the sign of an expression given a set of constraints. I have looked around and do see that there is a few threads on this but I'm not sure I ...
0
votes
1answer
32 views

How to solve ArcSinh equation for many differents parameters?

I am totally stuck trying to solve the equation below (1/2) x Sqrt[1 + 4 a^2 x^2] + ArcSinh[2 a x]/(4 a) == d Where a and ...
2
votes
1answer
412 views

Over 30mins to generate the first eigenvector?

Is it normal for Mathematica to take over 30mins to try to compute the first eigenvector of a 100x100 matrix? The matrix is reasonably sparse - about 90% of the cells are 0s and each column sums to ...
1
vote
1answer
32 views

How to form a variable from matrix elements

I have matrix with n rows and 2 columns, say m = {{x11, y12}, {x21, y22}, ..., {xn1, yn2}. Now, I want to form three new variables for example: ...
0
votes
0answers
27 views

Pick out element from array [on hold]

I have the $3\times 3 \times 3$ array: ...
0
votes
0answers
24 views

How can i insert mathematica graph in eps format into word file without lossing a right vertical line? [on hold]

How can i insert mathematica graph in eps format into word file without lossing a right vertical line? if any one know please help me
0
votes
0answers
43 views

Can not understand the code to make person curve

I'm reading the CDF file from Making Formulas… for Everything in wolframalpha blog. When I step into In[9] and In[10], I'm fully confused. Who can tell me what does the two functions mean? The ...
0
votes
0answers
38 views

Improve on timing of NMinimize

I got a little performance problem with the function NMinimize (it takes mathematica approximately 10 minutes to compute the results). Here i s my sample code: ...
1
vote
2answers
43 views

Randomly changing matrix entries

1.Write a block of code that generates a 4x4 matrix with randomized real number entries each between 0 & 1, then selects 3 matrix entries at random, and finally replaces these 3 entries with a ...
0
votes
0answers
20 views

Nested For loop in Mathemaitca for solving FDM problem

I am solving a FDM problem in Mathematica My equation is d[Rho]/dt + beta*Rho= alpha*q dq/dt + v*dq/dx +alpha*q= beta*rho nx = nt = 5; ...
0
votes
1answer
31 views

Non linear model fit

I need to fit this, but for some reason I cannot... data = {{0.617,0.8}, {0.605,0.6}, {0.5997,0.4}, {0.5972,0.2}, {0.5985,0.1}}; soln = NonlinearModelFit[data, {y - 2478.82*wlog[kc + 1]}, {y,w,k}, ...
0
votes
0answers
36 views

Using FindFit to return a list of possible best fits

Can I use some variant of FindFit that will return a list of the best fit and some worse fits, not just the best fit? This is for a function where the residual function can have several local ...
0
votes
1answer
25 views

How can I get numerical answers to integrals involving the error function?

This is the integral I am trying to evaluate in mathematica: Integrate[Exp[-p^2/(m w h)], {p, -Infinity, Sqrt[h m w]}] Can someone show me how to get a numerical answer out of this?
2
votes
2answers
25 views

How to delete certain unwanted elements from an array

Suppose I have an array like so array1 = {{Null,2,3,4,5}, {a,b,c,Null,e}, {w,x,Null,y,z}} Is there some way to selectively remove any element I ...
2
votes
5answers
113 views

Command to take the first elements of a list that match a pattern

I want to find the number of elements in a list in a row that match a certain pattern. So for this list {1,1,1,1,0,0,0,1,1,1} It should return "4" because there ...
0
votes
1answer
45 views

Submatrix with linearly independent columns

What I want is the submatrix where all the linearly dependent rows have been eliminated. I tried implementing this solution, but it doesn't work in the following example: ...
-4
votes
1answer
47 views

Trying to get plots to work AGAIN

OK, I have asked stuff here before. I am probably driving people crazy but this is making me angry and frustrated. And yes, I bet this is some simple syntax thing but I can't figure it out and I am at ...
0
votes
3answers
57 views

Showing the coordinates on a plot in TraditionalForm

I just want to show the coordinates (Log[y/x],Log[x/y]) of a point on a Graphics object, but TraditionalForm fails to convert ...
0
votes
1answer
83 views

Why is `B /. h -> #2 &` not a pure function?

I am trying to plot the energy surface of the mean field Ising model, but I am running into a problem with setting the MeshFunctions for the plot. ...
2
votes
1answer
51 views

Hilbert transform of density of states [on hold]

I am trying to evaluate analytical integration over density of states, for example G(Z)=int[f(x)/z-x,{x,x1,x2}] , where ...
0
votes
0answers
44 views

How should I provide Dataset slot names in function definitions? [on hold]

Say I have a Dataset like the following: ...
1
vote
0answers
36 views

ColorFunction - custom colors and scaling

I am trying to implement my own colors and scaling into the ColorFunction which I use in ListDensityPlot. I have several lists of 2D values which I plot in multiple images and I want to scale the data ...
1
vote
0answers
45 views

Optimization in MMA for time resolved spectroscopy

I want to fit some spectroscopic data with a model. I detect the fluorescence of something over different wavelengths. The detection over each wavelength is one data set in time. The lifetimes of ...
0
votes
0answers
41 views

How to display a list using numerical values? [duplicate]

Suppose I compute the eigenvectors of a matrix like this Eigenvectors [{{3, 2, 3, 1}, {2, 3, 1, 1}, {0, 0, 2, 1}, {2, 3, 2, 1}}] The result I get looks like: ...
0
votes
0answers
32 views

how do I multiply two arrays in Javascript? [on hold]

I want to multiply two arrays, as in element per element: [1,2,3,4,5] * [2,3,4,5,6] = [2,6,12,25,30] I am new to JS and just have no clue... Thanks, Pam
1
vote
1answer
37 views

Multiway Systems Rules List Management

I'm working with a multiway system and I have a number of different mutation rule lists. I need an efficient way of managing which rule lists I apply. Here is the basic multiway system code that I'm ...
0
votes
0answers
23 views

ErrorListPlot Not Plotting

I'm on Mathematica 6.0, it's the copy my school gave me for a lab course. ErrorListPlot produces a graph, but there is nothing on it. I have checked the table constructed using ErrorBar and it's good. ...
2
votes
3answers
88 views

How to do algebra on unsolved integrals?

I am working with functions calculated from a set of general basis functions. ...
1
vote
1answer
39 views

How to append data in an already existing data .txt file in newline or in tab separtion?

Say I have an already existing .txt file containing data in the following format. $a \qquad b$ Now at different times I will successively have data like ...

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