All Questions

0
votes
0answers
9 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: ...
1
vote
1answer
9 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
7 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
22 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
36 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 ...
1
vote
1answer
26 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
17 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
37 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
43 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
19 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
17 views

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

I've always had the Notebook Options > Evaluation Options > EvaluationCompletionOption set ...
0
votes
0answers
25 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
19 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
0answers
31 views

Plot time series group by Year

I have a time series dataset I'm trying to plot by Year: ...
0
votes
1answer
31 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
24 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: ...
3
votes
1answer
57 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
77 views

DumpsterDoofus's captivating generative art

How can I render these beautiful images that DumpsterDoofus posted?
1
vote
1answer
37 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
9 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
32 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
29 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
403 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
30 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
26 views

Pick out element from array [on hold]

I have the $3\times 3 \times 3$ array: ...
0
votes
0answers
23 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
42 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
35 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
40 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
19 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
29 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
33 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
24 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?
1
vote
2answers
24 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
112 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
44 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
46 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
82 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
50 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
42 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
81 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 ...

15 30 50 per page