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visits member for 2 years, 9 months
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Although I'm quite familiar with Mathematica, I always try to keep an open mind and don't use it as golden hammer. I'm particularly good at things that are fun, for instance


1h
comment Graph: PropertyValue changes and Dynamic
@LeonidShifrin The most unfortunate thing is that it is hard, even for advanced users, to look behind this curtain. One day everything works and you think you know how things are and the next day you cannot replace expressions inside Image or Graph and you have to find out the hard way that it is atomic now. And to say "Graph objects are atomic raw objects" in the very last paragraph of the help page doesn't help either, because it is not obvious what consequences this has.
1h
comment Graph: PropertyValue changes and Dynamic
@LeonidShifrin Exactly what I guessed and I'm stunned that WRI introduces mutability to such highly efficient objects as graphs, without incorporating this functionality into their flagship of advertisement: Dynamic. Btw, I saw that PropertyValue is quite old as it was introduced in V8. Surprising that no-one asked this question until now.
2h
asked Graph: PropertyValue changes and Dynamic
Oct
17
answered How to build a 3D graph from a 3D matrix?
Oct
17
answered Shortcut to erase the line one writes on, equivalent to Ctrl+k for pico?
Oct
16
comment How to Use Mathematica as a C/C++ compiler
@LeonidShifrin This clearly depend whether it is this one or this one.
Oct
16
comment How to Use Mathematica as a C/C++ compiler
@LeonidShifrin You just have to change your perspective.. for instance, if guys want to date pretty girls, they don't learn how to do this. Instead, they buy big cars and you know what, it works :-)
Oct
15
comment How to create a 1D vector by selecting a straight line in a given angle of 2D array
@AsafMiron Can you join Mathematica Chat to discuss what else than a line of pixel should be the result? Because this is exactly what I get out of your code: One line of pixels.
Oct
15
comment How to create a 1D vector by selecting a straight line in a given angle of 2D array
@AsafMiron hehe.. and without executing your code I see that you used {0,0} as starting point :-) List and matrices in Mathematica start with the index 1
Oct
15
comment How to create a 1D vector by selecting a straight line in a given angle of 2D array
@AsafMiron No, I don't know why. You have to ensure that your points $p_0$ and $p_1$ lie within your image matrix, but otherwise it's pretty fail-safe. I cannot run your code in the comment since it cropped.
Oct
15
comment List of tuples without forbidden pair
OK, reading the answer of Bob I suspect you don't really want to use real matrices but keep the symbolic a and b...
Oct
15
answered List of tuples without forbidden pair
Oct
14
answered How to create a 1D vector by selecting a straight line in a given angle of 2D array
Oct
14
comment How to create a 1D vector by selecting a straight line in a given angle of 2D array
The value for the variable dat is missing. I could not create any output graphics.
Oct
14
answered Suppress extrapolation of interpolating function in a ContourPlot
Oct
14
comment No output from Plot3D when run from a script
Let me make it more clear: There are different forms of output. When you want to print something to the console, then a terminal session of Mathematica, a redirect of a file into math or the -script mode will work. If you need to show a graphics, then this will not work, because you need a front end for this. When you run something as a script, then there is usually no need to display a graphics, because you want to automate some work or/and run several file in batch-mode. Can you please add more information about what you try to achieve?
Oct
14
comment No output from Plot3D when run from a script
No, it is not a limitation. In script mode (which you should invoke using -script option, see here) there is no front end, which is required if you want graphical output. In commandline-mode you can use JavaGraphics to display your plot, but when you run it as script, the window is closed immediately.
Oct
14
answered Trouble definining a function to use only certain heads
Oct
14
comment Suppress extrapolation of interpolating function in a ContourPlot
Try to restrict the call pattern by defining myfcn[x_/;0<=x<=1.5] := ...
Oct
13
comment Second order nonlinear differential equation
For this, DSolve is used, but apparently, Mathematica cannot solve your equation: DSolve[{y''[t] + 2*z*y'[t] + y[t] == A/(1 - y[t])^2, y[0] == 0, y'[0] == 0}, y[t], t] Even if you replace the unknown A and z with 1 Mathematica returns without result.