For questions specific to Version 7 of Mathematica.
2
votes
1answer
76 views
Export to mat file does not work
I use this command from the Mathematica documentation center
Export["1.mat", {"t" -> {{1,2,3}},"u" -> {{4,5,6}}}, "LabeledData"]
to save data as mat file ...
1
vote
2answers
99 views
How to blend some colors on a curve
I need to define a color gradient on a 3D curve, but I'm having some problems with this.
Suppose we have a 3D curve defined as a parametric function of some real variable ...
2
votes
1answer
56 views
How to extract the bin width from a Histogram made with an automatic binning method?
I am using the Scott binning method with Histogram and Histogram3D to plot some data. How could I find out the bin width chosen ...
7
votes
2answers
121 views
Tick marks shrinking with ImageResolution [duplicate]
High resolution PNG export is handy for print quality plots, however tick marks are not scaling properly. Does anyone know a solution or a work-around, preferably for M7 (on Win7)?
...
6
votes
0answers
68 views
Mathematica 7: “LessEqual::nord:” error when using NMinimize on a real function
I encounter a problem (Mathematica 7) similar to Strategies to avoid LessEqual::nord in NMinimize? but the advised strategies don't work for me. Also, I get different results with different ...
8
votes
2answers
177 views
3
votes
2answers
139 views
How can this DivisorSigma code be made fast?
Since Project Euler problems are now fair game for questions I have a question of my own.
A certain problem* states:
For a positive integer n, let σ2(n) be the sum of the
squares of its ...
7
votes
3answers
190 views
Plotting a 3D list causes kernel to crash if x and y axes have vastly different scales
I have access to two versions of Mathematica, version 7.0.1 on Linux and version 8 on Windows. When I try the following two lines on version 7, the kernel quits when it tries to plot. In version 8 ...
1
vote
1answer
105 views
Spacer and Text in Graphics going Awry (in Mathematica 7)
Use of a vertical Spacer in justified text inside a graphic isn't working as required. The result in the green box looks right, but when this is placed in a ...
3
votes
0answers
75 views
An recurrence equation that can be solved in version 7 but not in version 8
A friend of mine showed me this code sample:
RSolve[{a[n] == a[n - 5] + 1, Sequence @@ Table[a[i] == 1, {i, 5}]}, a[n], n] // Timing
It's solved by version 7 in ...
2
votes
1answer
133 views
Version 7 and 8, different behavior of NSolve. Is it reproducible?
I noticed the following difference, and I wonder if it's a problem of my system or the results difference is actually due to the two different versions
...
0
votes
0answers
187 views
Mathematica 9's NDSolve treats sum as an integral [closed]
Sum and integral are threated the same by NDSolve in Mathematica 9:
The problem was also in Mathematica 7. I submitted a bugreport to the technical support, they admitted this is a bug, fixed it in ...
1
vote
1answer
78 views
TextCell going awry due to ImageResolution (in Mathematica 7)
Can anyone see how to fix this text display? The example is from a larger project. I need to export the graphic at high resolution, but the text is going wrong.
...
0
votes
0answers
67 views
Error changing edge thickness in a GraphPlot
I'm having some problems with the Mathematica graphics inspector. I want to make a graph with the following code:
...
9
votes
3answers
251 views
Why does Hash return different values in Version 7?
This function does not work correctly for me. The generated Gravatars do not match the ones actually produced by using the corresponding address.
The problem was traced to differing output from the ...
2
votes
0answers
284 views
Simple contour integral with a parameter gone wrong
I run into the following problem, I tried to evaluate a very simple integral:
Assuming[ a > 0 , Integrate[Sin[a*s]/(s - I)^2, {s, -Infinity, Infinity}]]
...
1
vote
1answer
147 views
Version differences in Parallelize
I am having a problem which I guess is due to version difference. I have to generate a list of unitary matrices, which I can do easily. However I came to know about ...
2
votes
3answers
157 views
In Mathematica 7 for Windows, is it possible to use custom GUI magnifications?
I am running Mathematica 7 on Windows XP Pro. I often use the magnification feature to zoom in on Plots, ListPlots, and ...
11
votes
2answers
285 views
backward compatibility
When producing or enhancing code, it is tempting to use recent new primitives of Mathematica introduced in version 7 and 8, but for library code or in preparation or future version change in ...
6
votes
1answer
77 views
$InputFileName backwards compatibility
What would be a good replacement for $InputFileName (which has been added recently to Mathematica 8) to achieve backwards compatibility with let's say M6 and M7?
I ...
12
votes
2answers
255 views
Internal “Periodical” functions in version 7
In version 7 there exist these Internal` context functions:
?Internal`*Periodical*
...
12
votes
4answers
636 views
What is the right way to rotate an array?
Suppose I have an array, not necessarily square:
a = $\left(
\begin{array}{ccc}
1 & 2 & 3 \\
4 & 5 & 6 \\
7 & 8 & 9
\end{array}
\right)$
I want to rotate it like one ...
7
votes
1answer
519 views
Mathematica: Label specific vertices in GraphPlot
How can I label particular vertices in GraphPlot? And have the arrows space out accordingly, for the width of the label?
I have Mathematica 7, but I think this question applies to all versions.
...
6
votes
1answer
192 views
PrintTemporary in ParallelTable
I thought of a possible answer to Monitor doesn't work with ParallelTable but it doesn't work as I hoped it would.
This accumulates print cells instead of deleting them as intended. Can it be ...
4
votes
0answers
155 views
NullSpace[_, Method->“OneStepRowReduction”] is sometimes wrong; how can I work out when this happens?
(This is on MMA 7.0.1.0 on OS X)
I've just found a large matrix m for which NullSpace[m] and ...
7
votes
4answers
236 views
Unexpected behavior from GatherBy in version 7
I have come across what appears to be a bug in GatherBy. It appears similar to the problem of using Table[Random[], {1000}] in ...
