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http://community.wolfram.com/groups/-/m/t/1359321
edited to add: the keys needed to type a dot are esc-.-esc, but I still haven't found the documentation to that effect. Maybe I will write a program to record my long and frustrating travels through the Wolfram documentation.
Here is how not to find the answer: Start by typing esc-d-o-t; give up on that. Now go to the front page of the Documentation Center. Search "Dot". After realizing you have made another mistake, go back to the front page of the Documentation Center. Press random links until you find yourself on "Wolfram Language Syntax". Then you see "Mathematics & Operators", in orange, and under that you see a "+' and a "*" but not dot. Another dead end, or is it, because things in orange might be hyperlink, or they might not, and you won't know unless you take a gamble and try. Click it. Nothing. Lost the gamble. 20 more minutes killed, no dot, and no math done. When I was a kid, we would just push the #2 pencil into a piece of paper, and the dot would happen.
My little latex paper I'm writing has an index on the last page of all mathematical symbols used in the paper, scan the index, see a symbol, the index tells you what page the symbol is defined on, with a hyperlink to the definition....Joe Donaldson2018-06-19T22:30:21ZOrdered list of hyperlinks to all Mathematica tutorials?
http://community.wolfram.com/groups/-/m/t/1359354
Is there an ordered list of hyperlinks to all Mathematica tutorials, ordered like a table of contents would be?Joe Donaldson2018-06-19T23:09:30ZHow to enter Equal Symbol Aligned Math Cell without palette?
http://community.wolfram.com/groups/-/m/t/1359345
In the Writing Assistant palette I see a way to enter an Equal Symbol Aligned Math Cell, which would be useful both for input to be evaluated and also for formulas in the "DisplayFormula" cell-style. Is there a way to enter an Equal Symbol Aligned Math Cell without opening the palette or using the mouse?Joe Donaldson2018-06-19T23:03:55ZUpdate notebook after I changed a variable?
http://community.wolfram.com/groups/-/m/t/1357794
Hello,
I just started with Mathematica and coming from MathCAD because of its poor functionality in higher math.
Now I created a new Spreadsheet and was just trying around with some functions and variables.
Because I want to make some big calculations, I must have the possibility to sometimes changes some variables/functions at the start. Therefore i need the option to update my whole spreadsheet with these changes, without reentering all the later commands.
Greetings.ha bla2018-06-18T09:42:09ZSemicolon-Separated Expression-Sequences: How to Control Formatting?
http://community.wolfram.com/groups/-/m/t/1357032
Here is an illustration of what I mean by semicolon-separated expression-sequence:
x1 = 0; x2 = 3; x3 = 1;
When using the notebook interface to edit my code, sometimes Mathematica allows me to sequence expressions on a single line as illustrated above, but other times Mathematica forces each expression onto its own separate line. How Mathematica decides when to force the line-breaking is obscure to me (if it is documented, I have not found where), and so Mathematica's behavior in this respect appears random and surprises me when I'm not trying to be surprised by my editor. Is it predictable? Is it controllable?Joe Donaldson2018-06-17T05:00:49ZImplement Mathematica in Mathematica
http://community.wolfram.com/groups/-/m/t/1357709
Has anyone written Mathematica code simulating the Mathematica evaluation process (or at least some of its basics)? A Mathematica emulator (not the heavy math stuff like integration and reduce), written Mathematica, but using a small subset of Mathematica's functions? I hope one of you thinks it is fun, because it would be far beyond my ability, but the results would at least be helpful to new users trying to understand what Mathematica does. Once you learned said small subset of functions, you could understand the emulator's code; and once you understood the emulator's code, you would understand Mathematica. I cannot pay though, so I hope this sounds fun.Joe Donaldson2018-06-17T22:41:37ZPool Noodle Spikey
http://community.wolfram.com/groups/-/m/t/1356464
I made a [compound of 5 tetrahedra](http://mathworld.wolfram.com/Tetrahedron5-Compound.html). It's surprisingly sturdy.
![noodle spikey][1]
This was built with [pool noodles](https://www.amazon.com/dp/B01BY1S2US/). Noodles are 55" (about 4.5 feet) long with a 2 3/8" diameter. Cut in half these give a Length/Diameter ratio of 11.5789. How close is that to a perfect Length/Diameter ratio?
![pool noodles][2]
First, lets build up a dodecahedron with simple vertices and an edge length of 1.23607 or $\sqrt5-1$.
From that dodecahedron, find the ten tetrahedra with edge length $2 \sqrt2 $ .
Then find five disjoint tetrahedra. The following code works.
tup=Tuples[{1,-1},{3}];
gold=Table[RotateRight[{0, \[Phi], 1/\[Phi]},n],{n,0,2}];
dodec=RootReduce[Union[Join[tup,Flatten[Table[gold[[n]] tup[[m]],{n,1,3},{m,1,8}],1]]]/.\[Phi]-> GoldenRatio];
tetra=FindClique[Graph[#[[1]]\[UndirectedEdge]#[[2]]&/@Select[Subsets[dodec,{2}],Chop[2 Sqrt[2]-EuclideanDistance@@N[#]]==0&]],{4},All];
compounds=FindClique[Graph[#[[1]]\[UndirectedEdge]#[[2]]&/@Select[Subsets[tetra,{2}],Length[Intersection[#[[1]],#[[2]]]]==0&]],{5},All];
Manipulate[Graphics3D[{
Table[{{Yellow,Red,Green,Purple,Blue}[[n]],Tube[#,thickness]&/@Subsets[compounds[[1,n]],{2}]},{n,1,k}],
Table[{{Yellow,Red,Green,Purple,Blue}[[n]],Sphere[#,thickness 2 ]&/@compounds[[1,n]]},{n,1,k}]}, Boxed-> False, SphericalRegion->True,
ViewAngle-> Pi/10, ImageSize-> 650],
Row[{Control@{{k,5, "number shown"},1,5,1, ControlType->Setter },Spacer[15],
Control@{{thickness,.11, "thickness"},.08,.20,.01, Appearance-> "Labeled" }}], SaveDefinitions->True]
![Manipulate 5 tetrahedra][3]
The "perfect" Length/Diameter ratio for rigid tubes seems to be 11.8565. The half-noodle ratio is 11.5789. Since foam is forgiving, I figured that would give a tighter figure, and that turned out to be correct.
For a regular dodecahedron with edge length 1, the inradius and circumradius are 1.11351 and 1.40125.
For an edge length of 1.23607, the inradius and circumradius are 1.37638 and 1.73204.
Based on the sizes of the tetrahedra, we can find the scaling factor of 11.4021.
Height in inches is about 31 inches tall. Distance between vertices is about 14 inches.
The notebook also has a color template. And that's how to build a spikey from pool noodles.
[1]: http://community.wolfram.com//c/portal/getImageAttachment?filename=noodle5tetra.png&userId=21530
[2]: http://community.wolfram.com//c/portal/getImageAttachment?filename=noodles.png&userId=21530
[3]: http://community.wolfram.com//c/portal/getImageAttachment?filename=manipulate5tetra.png&userId=21530Ed Pegg2018-06-15T19:42:04ZIs Defer[] like single-quote from LISP?
http://community.wolfram.com/groups/-/m/t/1355524
I have been looking for something like LISP's single-quote. Is Defer[] it?Joe Donaldson2018-06-13T19:37:49ZExport strings without quotes to a .csv?
http://community.wolfram.com/groups/-/m/t/1357082
Writing a file from Mathematica for use by another program.
The output file will be a comma separated file.
Content of the file will be a combination of numbers and text.
The text in the output file should **not** have quotes around it.
Below is a sample data set and what I have tried so far.
row0 = {"h1", "h2", "h3", "h4", "h5", "h6"};
row1 = {"", "", "a1", 1.01, "", ""};
row2 = {"", "", "b1", 2.02, "", ""};
row3 = {"", "", "c1", 3.03, "", ""};
data = {row0, row1, row2, row3};
Export["data.csv", data];
Export["data.txt", data];
Export["data.dat", data];
Export["data.tsv", data];
Export["data.xls", data];
A summary of the results:
- data.csv -- has quotes around the strings
- data.txt -- has quotes around the strings and curly braces around each line
- data.dat -- no quotes around the strings, but the data is separated by tabs
- data.tsv -- has quotes around the strings
- data.xls -- no quotes around strings, data in appropriate columns, but this is an Excel file, which can't be read by the other program.
**One successful work-around:**: save the files as data.xls, then from Excel export to a .csv
Is there a way to Export the data so that it does not have quotes around the strings, but is separated by commas?
(Follow-up question: how to include quotes in some of the exported text. The Excel workaround fails for this case.)Robert McHugh2018-06-17T16:03:25ZReplacing functions and variables
http://community.wolfram.com/groups/-/m/t/1356010
Say I have $f(x,y) + \partial_x f(x,y)$ e.g.
fun = f[x,y] + D[f[x,y],x]
I would like to use the substitution $f(x,y) \rightarrow \delta^2g(\delta x, \delta y)$ to get a new function. I have tried various things such as
fun /. {f[x, y] -> \[Delta]^2 g[\[Delta] x, \[Delta]y]}
fun /. {f -> \[Delta]^2 g}
fun /. {{f -> \[Delta]^2 g}, {x -> \[Delta] x}, {y -> \[Delta] y}}
fun /. {{f[x, y] -> \[Delta]^2 g[\[Delta] x, \[Delta]y]}, {D[f[x, y],
x] -> D[\[Delta]^2 g[\[Delta] x, \[Delta] y], x]}}
none of which produce the desired output of $\delta^2g(\delta x, \delta y) + \delta^3\partial_xg(\delta x, \delta y)$. The last(4th) attempt seems to be the closest, but the output is a two element list, with each element having a correct and incorrect term.Derek Handwerk2018-06-14T21:09:53ZReinforcement Learning in Mathematica vs. System Modeler
http://community.wolfram.com/groups/-/m/t/1356924
Does anyone know of any links on the Wolfram site that could be used to benchmark implementing a reinforcement learning application in Mathematica vs. Wolfram System Modeler? There was one Mathematica [Reinforcement Learning Notebook][1] example but I am hoping to find a more complete example for each environment (Notebook & System Modeler) to help drive the decision on which to use to for our application.
Does anyone know of a good set of reference examples?
Thanks
[1]: http://community.wolfram.com/groups/-/m/t/1137429Robert Stephens2018-06-16T14:56:47ZDecrease a Dataset size in RAM?
http://community.wolfram.com/groups/-/m/t/1354318
Hi,
I have a question about the size of Dataset in RAM.
I have noticed that if i have a file .mx that contain a Dataset and the size on the HDD is for example 50 MB, when i import it in Mathematica the size in the RAM is about 10 times (500 MB)!
Do you know why there is so many difference between the two sizes? Is it normal?
I have noticed that if i save the same data as List and not as Dataset (without association) the size is just greater than the size in HDD.
Is there any solution that allows using the dataset without this "waste" of memory", because it is a big problem when i have to deal with a large amount of data... but the datasets are more "comfortable" than pure List.
Thank you for your help!Andrea Barresi2018-06-11T11:30:48ZCreate a user interface and stand alone application using Wolfram Language?
http://community.wolfram.com/groups/-/m/t/1355400
Hi,
I have a question about the creation of a stand-alone application and the relative user interface.
I have created many notebooks ok Mathematica using the Button, CreateDialog, Input Field and so on, but i have noticed that the code is hard to hide... For example, if there are some errors during the computation and Mathematica Print the errors, the hidden code appear...
Here is the question:
I have created a code for signal processing and data analysis. Are there a possibility to create a stand-alone application, that uses the Mathematica Kernel obviously but that appears only with buttons, menus etc. with which the user can interact to insert data, file path etc.. and start the analysis without seeing the code, in other words, an application with graphical user interface?
I'd like to create a user-friendly software for users that haven't any knowledge of Wolfram Language.
Thank youAndrea Barresi2018-06-14T13:39:57ZMove Notebook-Cell Brackets to the Left of the Window?
http://community.wolfram.com/groups/-/m/t/1353767
When my Mathematica-notebook window is maximized, most of the action is on the left of the window, but the cell brackets are far away on the window's right side. Is there a way to move the brackets to the left side of the window? If I find a way, I will try to include it in my default style-sheet.
Unrelated question, but small so I'll throw it in here: Is there any keyboard shortcut to move the cursor from a cell's interior to a space between cells? Or a shortcut to immediately select the cell containing the cursor (assuming the cursor is inside a cell)? These would facilitate mouse-free navigation (which is my favorite thing about Emacs).Joe Donaldson2018-06-10T14:49:24ZWhere in the docs for the IFF keyboard shortcut?
http://community.wolfram.com/groups/-/m/t/1356022
When I'm thinking about math, and I need to type the if-and-only-if symbol, but esc-iff-esc doesn't work, and then I search the docs for 15 minutes, then Google, but still can't find the right key-sequence to type (what was I working on before this? can't remember offhand), where exactly in the docs should I be looking for information I need about which keys to press, please?Joe Donaldson2018-06-15T01:02:25ZDisplaying Databin as a Dataset table in a FormFunction Cloud Deployment
http://community.wolfram.com/groups/-/m/t/1355333
I am trying to set up a cloud deployed FormFunction where a user can enter a public databin ID and then view the contents formatted as a dataset. I keep running into issues where the output of the form returns straight text rather than the table I am looking for.
CloudDeploy[
FormFunction[{"Databin ID:" -> <|
"Help" -> "Enter the ID of a public Databin",
"Interpreter" -> "String"|>, },
Dataset[Databin[#"Databin ID:"]] &], Permissions -> "Public"]
And here is a snippet of what I am getting in return when I try to view the databin as a dataset:
Dataset[{<|"Name" -> "Ben", "Email" -> "fake@gmail.com","Timestamp" -> DateObject[{2018, 5, 18, 12, 26, 55.98299980163574}, "Instant", "Gregorian", -7.]|><|"Name" -> "bob", "Email" -> "anotherfake@gmail.com","Timestamp" -> DateObject[{2018, 5, 18, 12, 30, 33.210999965667725}, "Instant", "Gregorian", -7.]|>.....
I can replace
Dataset[Databin[#"Databin ID:"]]&`
with this
ExportForm[Dataset[Databin[#"Databin ID:"]], "PNG"] &
and it will display an image of what I am looking for, but any other formatting option ("HTML", "WL", etc.) either fails or returns the same string of text as before
Any idea what I am missing?Ben Kickert2018-06-14T01:08:22ZExtract internals from a ParametricFunction object?
http://community.wolfram.com/groups/-/m/t/1355264
If I create a ParametricFunction object for doing ParametricIPOPTMinimize, how can extract the variables from the object?Frank Kampas2018-06-13T21:17:11ZSuggestion: mathlink.h / wstp.h shouldn't include <windows.h>
http://community.wolfram.com/groups/-/m/t/1355822
If it is at all technically feasible, it would be useful (or rather: user-friendlier) if `mathlink.h` did not include `windows.h` on Windows systems.
Recently I had a very frustrating experience where a C++ library wouldn't work on Windows when used in conjunction with MathLink. The problem turned out to be that the C++ library uses the names `IN` and `OUT` internally, but `windows.h` defines these as macros. It also defines many other macros which have a potential for conflict and difficult to debug situations.
It took quite a while to debug because the code was working fine on OS X / Linux, so at first I thought that the problem was with the Microsoft compiler. Then I realized that it was related to including `mathlink.h`, but it took some more time before I managed to find the relationship to `windows.h` and [the unexpected `IN`/`OUT` macros](https://stackoverflow.com/questions/35907493/in-and-out-macros-in-minwindef-h).
I am not experienced with Windows programming, and it is not clear to me if it is feasible to drop the `windows.h` dependency from `mathlink.h` for a future version ... I noticed two places where it was actually needed:
- For the `WinMain` function that `mprep` generates. This is not an issue as the `#include <windows.h>` can be moved to `mprep`'s output.
- For the `FAR` macro. But this has been obsolete for many many years now anyway.
[@John Fultz][at0], do you think it would be possible to remove the `#include <windows.h>` from a future version of `mathlink.h`/`wstp.h`? Or are there still-relevant technical reasons to keep it?
Does anyone else see a reason why doing this is not technically feasible?
[at0]: http://community.wolfram.com/web/jfultzSzabolcs Horvát2018-06-14T10:31:55Z