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Oct
10
comment Very serious multiplication bug when subscripts are used
@physicsphile Good to know they acknowledged the bug.
Oct
9
comment exporting mathematica videos
The question at this point seems too broad because there are so many ways to make movies. The title suggests that you want to Export videos from Mathematica. In that case, you would have to be more specific about the source objects that you want to export, and the movie format that is desired. It's not efficient for someone who wants to answer, if they first have to download the iBook you mention, in order to see what you might mean.
Oct
9
comment stacking images
Unless we get more details about the images, and an explanation of what this has to do with "stacking" them, I would call this a duplicate of the question linked by @Kuba.
Oct
9
comment Non sequitur in documentation of MemberQ
That historical explanation of why they put the wording in the front section seems to make sense (+1).
Oct
9
comment Non sequitur in documentation of MemberQ
I'm going by my knowledge of what all the other functions ending in Q also do. They differ from tests such as Element in that they assign a truth value based on the immediate, explicit structure of the argument. Think of TrueQ: it's very quick to give False because it only gives you True if you give it True first. In other words, functions ending in Q don't ever give "maybe" as an answer...
Oct
6
comment Explanation for coloring of variables by code editor?
What happens when you check the definition of r by doing ??r ?
Oct
6
comment Explanation for coloring of variables by code editor?
The screenshot has a gap in between line 132 and 136. If you want a real explanation of why r is blue after line 132, you have to post the actual, copyable code sequence without gaps that leads to the coloring you are showing here.
Oct
6
comment Explanation for coloring of variables by code editor?
I can't tell from the screenshot what happened in your notebook between the point when r was defined and when it reappears later. It may have been cleared in the meantime. Once a variable is subjected to Clear, Remove or =. it will again be undefined and appear blue everywhere in the notebook, even at earlier points. But sometimes it does happen that Mathematica doesn't immediately recognize a previously defined symbol and incorrectly leaves it blue.
Oct
5
comment Mathematica exported movie quality
@JasonB is right - you may want to have a look at this answer where I discuss some other file formats for movie export, and at this answer for how to export image sequences to create the movie externally. However, you can get better result from within Mathematica, too, if you rasterize the image frames at the resolution you like before exporting them. That is discussed here.
Oct
5
comment Using an Image as the Fill/Texture (not background) of a Plot (not polygon)
I thought your main goal was to show the image only under part of the curve, like the colored regions in the sine plot you showed. If not, things are much easier (see other answers). To make the image fit the entire plot, you of course have to make sure that the aspect ratio of image and plot are identical. This could be done (a) by stretching the image, (b) by choosing an image with the right aspect ratio, or (c) by setting the aspect ratio of the plot equal to that of the image. You'd have to decide first which of these options you want. I mention option (a) in my answer.
Oct
5
comment Very serious multiplication bug when subscripts are used
@RolfMertig That's indeed good advice. Subscripts are in general full of pitfalls, especially for people who don't know anything about DownValues... But this seems to be a good test case showing a shortcoming of the parser that looks fixable.
Oct
5
comment Very serious multiplication bug when subscripts are used
@belisarius I confirmed this in version 8 and answered based on what I saw there. I strongly suspect that it's the same in version 10.
Oct
5
comment Using an Image as the Fill/Texture (not background) of a Plot (not polygon)
To avoid wasted effort, could you please include the code for the actual DateListPlot that you are working with?
Oct
4
comment How can this texture be inserted in the beginning and the end of cylinder?
You got this code from my answer here. It would have been better to include a link to that in your question, because nobody likes to see a bunch of code without explanation and context. So by beginning and end you mean the bottom and top faces of the cylinder?
Oct
4
comment NSolve super slow for a parameter scan
That just requires some reshaping of the result. E.g., if the output from above is called ans, then one could do Thread[{d,f}->({d,f}/.Flatten[ans,1])] (where Thread adds the Rule arrow to each list of d and f values, resp.
Oct
4
comment How to get Mathematica to draw soft edges?
Also related: Sketch-type graphics with transparency and dashed hidden lines?
Oct
3
comment Leave out a term when summing
@BobHanlon Yes indeed. THese are my favorite kind of sums - the ones where you get to pick what the answer is...
Oct
1
comment Controlling PointSize in a RegionPlot
(+1) Maybe you can include a comment regarding the difference between Point in a RegionPlot and in Graphics: the ability to include Point in RegionPlot as done in the question is due to the fact that Point can be interpreted as a "region" just like e.g. a Disk can. But in that interpretation (which depends entirely on the context being RegionPlot), it's impossible to use styling the way one expects it to work for the Graphics primitive Point. These are basically two different incarnations of Point, and the styling only works when removing it as a RegionPlot argument.
Sep
30
comment How to get `Series` to recognize user-defined function has pole
You reference to Gamma is confusing because it doesn't actually do what you seem to be asking for in the question. E.g., Gamma[1/3] doesn't evaluate even though the argument is numeric. Obviously your question wants that to evaluate, too. So I don't know what the real goal is.
Sep
29
comment What is the recommended way to define numeric function with special cases?
@RunnyKine OK thanks, I edited that in as well...