"rubber duck debugging" - I vastly prefer the term originally used by McConnell: "confessional debugging". And yes, it is a frequent case for me: attempts to write a question in an easily understood form often leads me to solutions.
@barznjy, as noted by Michael, in calculus as well as in Mathematica, there are special rules for handling limits/integrals/sums/whatever that have infinity in them. Mathematica has those rules programmed in, so that it does what is (usually) expected.
@Guesswhoitis. Will do when I get to my office tomorrow - I've got MMA working on this display for the RPi and want to tweak X and MMA to make the experience a bit more inviting.
@halirutan Do you know how shared libraries are handled on Linux? I really don't know much about how dynamic linking works and I'm running into this problem: I compile a LibraryLink library that depends on some pre-installed package on Linux. It appears to link to this package dynamically when compiled with the default settings. Now my LibraryLink library will only work if I explicitly LibraryLoad the dependency.
Is there a way to avoid having to explicitly LibraryLoad that?
Earlier today, had a file go corrupt
The WR documentation gave a solution that didn't work. So I posted this Question:
How to restore corrupted files?
In the first Comment, @belisarius posted a link to pertinent Search results. I clicked through every link, which led me to several un-Answered ...
@Szabolcs I don't have to load every library my programs use, but the specific non-standard things, yes.
@Szabolcs I'm using something like this in my init.m and it works on all three operating systems:
$ipcuFound = FindLibrary[$ipcuLibrary];
If[ $ipcuFound =!= $Failed,
$ipcuDependentLibs = {};
Which[
$SystemID === "Linux-x86-64",
$ipcuDependentLibs = {"libtbb"},
$SystemID === "MacOSX-x86-64",
$ipcuDependentLibs = {"libtbb", "libiomp5"},
StringMatchQ[$SystemID, "Windows*"],
$ipcuDependentLibs = {"tbbmalloc", "tbb", "libiomp5md"}
];
(* Load the dependent libraries before the functions from the ipcu_library *)
Check[
LibraryLoad /@ $ipcuDependentLibs,
Message[ipcu::ldlibs]
@Szabolcs And I should tell you that, although it doesn't crash, Mathematica gave me an error message on Windows too when I did not pre-load the libs. Was hard to find out, because the message was pretty unspecific.
So it took a long while until I found out it is the dendency-lib that was making trouble and not my own.
@halirutan It's my igraph stuff. Today I tried to make it work on Linux (Ubunut). I simply installed igraph with apt-get, linked against it with -ligraph, and this made it link dynamically.
now I have to do LibraryLoad["/path/to/libigraph.so"] before loading the package, to avoid a crash.
LibraryLoad["/usr/lib/x86_64-linux-gnu/libigraph.so"] works. But I didn't expect this kind of problem and I'm not really prepared to deal with having to explicitly set library locations when I'm not shipping the library ...
@halirutan Yes, it seems so. But how do other software that depend on it find it then? I assumed it got installed system-wide. Do you know what the 0 suffixes mean in ubuntu, i.e. why this was called libigraph0 instead of libigraph?
@halirutan Perhaps the default linking on OS X was static? I didn't have the problem on OS X. (Sorry, had to step out for a moment). yes, I'm looking into how to link it statically without making it too painful to keep using CreateLibrary.
@Szabolcs AFAICS everything is hardcoded. I had to rebuild my own lib. This has the same disadvantages as they exist in Ubuntu, because the header and library locations are specific to my machine :-(
@mikeonly it is also better if you delete unnecessary image elements using an image editor before digitizing the points. Although that doesn't seem to have been a problem for you in this case
Then I do "Copy Coordinates" and save them to a set pointsOnImage.
After that I try to find a transformation: `trans = FindGeometricTransform[{{0, 0}, {0, -500}, {4, 0}}, points, TransformationClass -> "Similarity"][[2]]`
{{0, 0}, {0, -500}, {4, 0}} is a set of coordinates that should be a result of trans when it is applied to points set.
@mikeonly You need to learn to debug! The first clue would have been, why you input image has a white background and your output image a black background :-)
@Guesswhoitis. Here's the notebook that shows up every time the RPi version of M starts. It is called MathematicaNavigator.nb and I found that it is being loaded whenever DefaultFrontEndInit.tr is being parsed. Removing reference to the notebook in that tr file did the trick.
@Guesswhoitis. I suspect it's intentional since that's the only (obvious) way to get at the documentation - which for the RPi is only accessible on line.
Do you happen to know how to evaluate a notebook at startup and keep it persistent? Using the -ne argument (e.g. mathematica -ne notbook.nb runs the notebook but then exits.
But nobody responded, of course it was not in Putonghua
And I suspect that is the issue
My question is -- Do you have any connections/ideas/friends that sell electronics/people in general -- that can point me to a website/storage/shop/whatever that sells those
Suppose that for certain reasons we are not yet using Mathematica version 10, or we have a version with buggy PlotMarkers. It is well known that the default markers are font glyphs, and as a result they are difficult to size consistently, as well as exhibiting inconsistent alignment. Because of t...
@Edmund find a font that has these drawn out. Then produce a PDF containing the character and import the character as an outline as Alexey shows. This is the simplest way to get such shapes
@Pickett Can you test this work-in-progress package? Installation: extract, place the directory in $UserBaseDirectory/Applications. Test: <<IGraphM` , then IGVersion[], then IGBetweenness@RandomGraph[{10,20}], then IGBlissCountAutomorphisms[PetersenGraph[5,2]]. There should be no messages and please make sure the last one didn't crash.
posted on September 02, 2015 by Giulio Alessandrini
I’ve taken pictures numerous times, either with a camera or with my phone, only to find out that the colors were completely off—they had bluish, reddish, or even greenish tints. Before I started working on image and color processing, this was quite mysterious to me. Moreover, I’d always noticed on my cameras a white balance [...]
Get ready for the flame wars to hit credit-card-sized computers. Matlab is now available on the RPi, although it looks like they aren't offering it for free as does Wolfram.
Comment space is very short.
Sometimes I have a very long comment where I would like to have the same capabilities as are available for Answers (e.g., paste long lists, show code, figures, ...) in order for my comment to be understood.
I haven't done this yet but I could write the Comment as an...
I have this equation to begin with:
$$1 - 3 x y = 5 z - 2 x $$
I want to solve this equation for $z(x,y)$, then plug $z(x,y)$ I plug $z$ inside a second equation:
$$ y = 7 x z - \frac{z}{x} $$
Finally, I want to plot $y(x)$ for $-5 < x < 5$ and $-5 < y < 5$. I tried numerically, but the fo...
Hi I have these pair of equations to solve:
$$ 1 - 3 x y = 5 z - 2 x $$
$$ y = 7 x z - \frac{z}{x} $$
I want to eliminate $z$ and plot $y(x)$ within the range $-2 < x < 2$ and $-2 < y < 2$:
I tried this code, but not sure why it's not working:
eqn1 = 1 - 3 x y == 5 z - 2 x
eqn2 = y =...
I start with this equation and solve it numerically for $z(x,y)$ in the range $1 < x < 5$ and $1 < y < 5$:
$$ \frac{3}{xyz} - 2x - 3y - 5z = 0 $$
Then using the data points of $z$ above, I want to solve for this special condition:
$$ x + y + z = 0 $$
Then I want to plot a graph of $y(x)$. E...
Earlier today, had a file go corrupt
The WR documentation gave a solution that didn't work. So I posted this Question:
How to restore corrupted files?
In the first Comment, @belisarius posted a link to pertinent Search results. I clicked through every link, which led me to several un-Answered ...
Comment space is very short.
Sometimes I have a very long comment where I would like to have the same capabilities as are available for Answers (e.g., paste long lists, show code, figures, ...) in order for my comment to be understood.
I haven't done this yet but I could write the Comment as an...
