All Questions
2
votes
0answers
31 views
NIntegrate/NSum with parameters [duplicate]
I'm trying to calculate a continuous integral within a discrete integral.
Something similar to this (yet more complex):
...
1
vote
2answers
62 views
Scaling the x-axis in ListLogLogPlot[] or ListLogPlot[] in lieu of DataRange
I will present my existing workaround but I am wondering if there is a better solution that takes less time (my solution seems to ~double the time it takes to produce the desired plot). Using ...
1
vote
0answers
85 views
NDSolve diffusion equation over/underdetermined
I have a feeling the solution to my problem is very simple… but my knowledge of differential equations is pretty weak.
I am trying to solve a scalar diffusion equation (used in NMR spectroscopy, but ...
1
vote
1answer
105 views
1
vote
1answer
64 views
Given a list of date and value pairs, efficiently sum the values by date
I have a list of date & value pairs. There can be multiple entries for each day. Sample data can be generated with the following:
...
0
votes
0answers
30 views
Expressions like <<1>> [duplicate]
In a function where I call the Maximize function, I am getting an error that says
...
0
votes
1answer
108 views
DAE - varying initial conditions
I want to solve a DAE-system and I want to vary more than one initial conditions and to manipulate them. I looked here:
Putting NDSolve into ParametricPlot
But it does not work:
...
5
votes
1answer
60 views
Importing images from the web using ImportString & URLFetch
I can bring images from the web using the Import command like this:
Import["http://blog.wolfram.com/wp-content/uploads/2008/06/se-30.jpg"]
Sometimes the web ...
2
votes
0answers
95 views
I am missing a function like HoldPattern
Temporary message: I am planning to edit this question, making the examples less confusing and by moving the things that are confusing to a separate question
For any confusion about expressions that ...
0
votes
1answer
66 views
Integrate of Heaviside Function returns an error answer
I try to evaluate an Integral of a Heaviside function, but it turns out with an erroneous output(zero). Here is my integral:
...
1
vote
2answers
78 views
Reversing the ColorScheme used in an ArrayPlot and setting the font size in the color bar
I have a matrix of data that I am plotting via ArrayPlot.
...
25
votes
1answer
421 views
Finding areas of beings in microscopic image
I've got lots of images of diatoms. I need to get a list of their equivalent radii.
It's not crucial to get them all, as long as those missed don't mess with the radius distribution (as would ...
7
votes
3answers
133 views
Making large tables easy to read with frozen headings and scrollbars [duplicate]
I would like to represent a table containing a large amount of information in such a way that I can (a) use scrollbars and (b) have table headings that don't scroll off the screen [just like the Free ...
13
votes
3answers
169 views
Common subexpression from two expressions
I am working with some unpleasantly tedious polynomials, which need to be manipulated in various ways (integrate with respect to some variable, differentiate with respect to another). Since these ...
1
vote
1answer
69 views
How can I change the Graph required data such as EdgeWeight,VertexWeight,EdgeCapacity,VertexCapacity in the Graph?
I asked this question in different form and because I couldn't receive the proper answer so I have to change my question.I know that was my fault sorry.I need to change the Matrix Data of nodes and ...
2
votes
0answers
66 views
Exporting plots
I want to export a plot which includes curve fitted to a multiple data set.
shortly ( I use autolegend function Here )
...
1
vote
3answers
99 views
The plot of roots of polynomials
I have polynomial equation like Tribonacci Polynomials for example: $T_3(x)=x^4+x$.
After finding the roots of this polynomial, I want to show these roots in the complex plane.
I have tried lots of ...
0
votes
1answer
48 views
Table of Polynomials [closed]
I made a function
makePolynomial
that creates a random Polynomial of a certain degree, e.g.
2+T+3T^2+8T^3-5T^4...
now I ...
6
votes
0answers
106 views
Symbolic integration in real domain only ( assumptions and ComplexExpand don't work)
Integrate[m^2/((x - m^2)^2 + y^2), m]
mathematica gives me a complex-valued reuslt, but maple 17 gives me what I want.
I tried using assumptions, but it doesn't ...
1
vote
1answer
98 views
Safe values of $\mu$ and $\sigma$ when randomly sampling from a Log-Normal Distribution?
I believe I'm obtaining overflow errors when randomly sampling from a log-normal distribution with the command:
RandomVariate[LogNormalDistribution[μ, σ], 1]
...
1
vote
1answer
113 views
Computing Correlations and p-values
I have two vectors $A$ and $B$ of length (say) $50$ or so, and I want to determine whether there is any correlation between their entries. I computed their correlation directly and found it to be ...
0
votes
0answers
42 views
Collect and factor equations with certain terms
Collect user defined terms from a symbolic algebraic expression
...
0
votes
0answers
86 views
Computation results returned as image instead of text
Some times my Mathematica return the result of any computation as text, I don't know why, and how to revert it. If I close and open again, it comes back to normal.
As you can see, the mouse cursor ...
0
votes
1answer
71 views
Taking derivative of Euler relation [closed]
I have defined the following function, which is the Euler relation for $\cos\,x$.
f[x_] := 1/2*(Exp[I*k*x] + Exp[-I*k*x ] )
I want to take the derivative with ...
4
votes
2answers
213 views
Simplify — is this simplest result Mathematica can provide?
I have a question about Simplify: When I do a simplification the returned result is not as simple as I want. When I ask for the Norm of an complex expression, ...
-2
votes
0answers
61 views
Maximum root by using `FindRoot` [closed]
Assume f[x_, y_,z_] :=
Block[{A}, FindRoot[Abs[r[x, y, z]] - w[z] + 1 == 0, {A, 100}]] where ...
7
votes
1answer
160 views
Simple problem with Manipulate and Plot
Would anyone have an idea why the following doesn't work:
rule = {z -> x^2 + 2 x + y};
Manipulate[
Plot[z /. rule, {x, 0, 10}],
{{y, 2, "y"}, 1, 5}
]
But ...
1
vote
3answers
125 views
How to collect/reduce with respect to multiple variables?
I have this code:
a == b + c + d - e
Is it possible to collect or reduce this expression into this:
c + d == a + e - b
...
1
vote
1answer
117 views
No anti-aliasing on BarChart3D?
If I put AA code in BarChart3D, it won't works. Here is the code.
...
10
votes
2answers
265 views
Visualizing vector spherical harmonics
I have painstakingly derived the vector-spherical harmonics $\mathbf{V}_{J,\,M}^\ell(\theta, \phi)$, which are the generalization of ordinary spherical harmonics $Y_\ell^m(\theta, \phi)$ to vector ...
0
votes
0answers
9 views
Fractal Analysis [migrated]
Is there any way to compare two fractals and analyse the difference between the two. I'm doing a project on fractals and It'll be very easy if there is a module which can be used to analyse and ...
7
votes
0answers
83 views
Compile not correctly initializing a variable defined inside Module
In the following example, inside the minimumX's Module, x is initialized to 1, but the ...
-2
votes
0answers
88 views
How to type function terms into metric?
I submitted my question before on site:Anything wrong with Atlas 2 or Mathematica?. Due to my vagueness, my problems might not be clearly understood.
I am trying to solve several functions based on ...
0
votes
0answers
46 views
11
votes
2answers
179 views
Where to begin? [duplicate]
I was looking at the Mathematica website today and just decided to buy the software. I've spent too much time juggling annoying symbolic expressions by hand that actually learning to do things with a ...
4
votes
2answers
103 views
4
votes
2answers
162 views
rotating 3d text
Is it possible to create a 3d rotating text like this:
animation here.
Here is my try so far:
...
0
votes
0answers
49 views
LogLinearPlot analog for Plot3D? [duplicate]
Is it possible to make 3D plot in logarithmic coordinates? I need analog LogLinearPlot to plot 3D figure in logarithmic x, or y, or both coordinates.
4
votes
2answers
120 views
find where 3 inequalities are simultaneously greater than zero
I have 3 functions, f11[l], f12[l] and f13[l], and I would like to know for which values of l these 3 functions are greater than zero. How do I do it analytically or numerically or graphically in ...
2
votes
1answer
77 views
Tough Inverse Fourier Integral: why does the sign matter?
I'm computing the Inverse Fourier Integral of
((a^2 + omega ^2) c^2)
/((b^2 + omega^2) ((r^2 + omega^2 - omegaInt^2)^2 + (2 omegaInt r)^2))
...
8
votes
1answer
108 views
Apply a Function Pairwise
I'm new to Mathematica
I'd like to apply Mean pairwise to a list to achieve the following.
...
4
votes
1answer
147 views
Track object movement
Referring to this link I happen to realize that actually the trace being projected is dependent on an equation and not on disk or circle. Though I was presuming that it is getting traced because of ...
0
votes
2answers
131 views
0
votes
1answer
76 views
financial data behind Wolfram|Alpha and Finance Platform
I need to price 23,000 securities from 1999 to 2007, and they are surprisingly hard to find on subscription-based services, like Bloomberg LP, ThomsonReuters or S&P CapitalIQ offerings. Probably ...
16
votes
2answers
356 views
3D orbits and inaccuracy over time
I wrote a little program to use Newton's Law of Universal Gravitation to animate 3 planets orbiting a central star, but I have run into a problem. Here is the code that I used to create the program (I ...
5
votes
1answer
145 views
How to draw some 2D curves in a 3D plot?
I want to plot several 2D curves (Sin[x] at y=0, Cos[x] at ...
7
votes
2answers
132 views
DumpSave for the forgetful
A few weeks ago I created a big matrix, and in order not to have to recreate it, I stored it using DumpSave["file.mx", variable]. Now I want to read it back in and ...
1
vote
1answer
79 views
Prandtl-Meyer function
I'm trying to solve for Mach number based on the given Prandtl-Meyer function, however I keep getting odd error.
Here is my code:
...
2
votes
2answers
78 views
Mass Symbolic Manipulation with Subscripts? (from plaintext Input)
The simplest example of the change being sought is a greek letter, typed in as plaintext nu, and its may be replaced by the symbol, ν:
expr = 3nu*kx*ky+ ...
4
votes
2answers
95 views
Convert Graph to Graphics
In Mathematica 9, a graph is returned as an object with head Graph:
In[8]:= CompleteGraph[8] // Head
Out[8]= Graph
...
