All Questions

0
votes
0answers
19 views

Using FindFit to return a list of possible best fits

Can I use some variant of FindFit that will return a set of best fits, not just the best fit? It would be very useful if for example I had a list of "best fit" parameters, arranged by residuals. ...
0
votes
0answers
12 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
1answer
19 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: ...
2
votes
2answers
75 views

ContextPath and autocompletion with subpackages

I'm developing a larger package which includes several subpackages. My problem is, that I can't introduce the symbols in the subpackages to the autocompletion by loading the main package, but by ...
0
votes
0answers
15 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
28 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 ...
0
votes
0answers
24 views

Plot time series group by Year

I have a time series dataset I'm trying to plot by Year: ...
1
vote
1answer
13 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
13 views

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

I've always had the Notebook Options > Evaluation Options > EvaluationCompletionOption set ...
8
votes
4answers
230 views

Rotated Rectangles

I would like to produce an image similar to the upper half of this graphics by Victor Vasarely. All I could produce so far is this dilettante image: ...
1
vote
1answer
26 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
0answers
15 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 ...
3
votes
3answers
211 views

How can we plot the complex roots of an equation?

If we'd like to display the $n$ roots of a polynomial on the complex plane as points, how can we do this? For example, if we have the equation $x^3 + x^2 + x + 1$, how can we plot the 3 roots as ...
0
votes
1answer
25 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: ...
23
votes
7answers
6k views

Even Fibonacci numbers

Today, I found the Euler Project. Problem #2 is Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be: ...
3
votes
1answer
35 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 ...
1
vote
1answer
26 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 ...
8
votes
0answers
70 views

DumpsterDoofus's captivating generative art

How can I render these beautiful images that DumpsterDoofus posted?
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 ...
22
votes
6answers
3k views

Fixing quirky typesetting in plot labels

Consider this example plot. Plot[ 1-Exp[-x], {x,0,3}, AxesLabel->{"thickness (μm)","power density (W/m^2)"} ] Let us hold the typographical quality of ...
0
votes
0answers
8 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 ...
0
votes
1answer
112 views

Plotting Integral equation

I want to plot the following indefinite integral : $C_l^{CC}=\int k^2\mathrm{d}k\: [e^{-2k^{2}}P_{Cl}^2(k\eta)|\dot{h}(\eta)|^2]$ with k from 0 to some large value (considered to be $\infty$), ...
1
vote
1answer
25 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: ...
2
votes
1answer
273 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 ...
0
votes
1answer
24 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 ...
0
votes
0answers
33 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: ...
2
votes
0answers
37 views

Mathematica AppData folder is taking up too much space

I recently made a small app that I had issues with. I'm pretty sure it ended up being because of all the curated data to load. My problem now is that under the Windows 8.1 folder ...
0
votes
1answer
41 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: ...
2
votes
5answers
111 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
0answers
26 views

Pick out element from array [on hold]

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

How to get grid items with a gradient background to behave well?

I have a table that looks something like this ...
1
vote
1answer
45 views

Graph objects for LineGraph

When I enter for example G = Part[GraphData[10],1]; LG = LineGraph[G]; I get error message that LineGraph requires a graph ...
16
votes
3answers
4k views

Implementing discrete and continuous Hilbert transforms

What is an efficient and accurate Mathematica implementation of the Hilbert transform, for both continuous and especially discretely sampled functions? This transform relates phase and amplitude in ...
0
votes
0answers
41 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
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
6
votes
3answers
109 views

Defining a custom Plus for a specific class of arguments

I'm trying to develop an domain-specific language with Mathematica. I want to define a customized behavior for the Plus function when applied to my data. For ...
0
votes
1answer
28 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
18 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
23 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?
-4
votes
1answer
45 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 ...
2
votes
1answer
49 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
1answer
81 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. ...
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 ...
1
vote
2answers
23 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
2answers
66 views

How to do algebra on unsolved integrals?

I am working with functions calculated from a set of general basis functions. ...
2
votes
1answer
95 views

Dynamic process on graph

I have a question, which I failed to find an answer to myself. I'm a casual user of Mathematica, but do have some knowledge about Dynamic module and other "Advanced" features. My problem is ...
1
vote
2answers
113 views

Symbolic combinations

If I have 3 lists: {a,a},{b,b},{c,c}, then the desired output is ...
0
votes
1answer
72 views

Use separate options for different elements in Show

I have a few plots of different type. plot1 has gridlines and the rest do not. I use the option Method -> {"GridLinesInFront" -> True}] when plotting plot1. When I use Show to combine the plots the ...

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