19
votes
Accepted
Interpretation of the result of ?@
The full form of ?@ is Information["@", LongForm -> False].
LongForm -> False...
- 107k
10
votes
Accepted
How to obtain the computer's hard drive serial number, BIOS ID, CPU number, MAC and so on use Mathematica?
According to Oleksandr R. wmic can only be run by Administrators.
Here is how you get the Serial on Windows.
Import["!wmic bios get serialnumber", "Text"]
To get ...
- 7,565
8
votes
Accepted
variable K cannot be deleted
The Wolfram Language currently uses seven single letter capital letters for various core system functions: C, D, ...
- 9,741
7
votes
Accepted
How to reset a built-in symbol to its default definition?
If the System` symbol you want to modify is a kernel function, then you can just use Clear to reset it to its default state. For your ...
- 129k
7
votes
Items known by CurrentValue
The secrets can be revealed by examining strings in the executable file:
...
- 684
6
votes
Items known by CurrentValue
Another way to get more stuff is to just see what's available to FrontEnd`Value[FrontEnd`CurrentValue[__]] as that's how ...
- 46.6k
6
votes
Items known by CurrentValue
Since many people seem to be looking through files in text editors I thought I'd give a way to scrape this data automatically (it should work for any kind of expression you want, as long as it's in a ....
- 46.6k
6
votes
How to obtain the computer's hard drive serial number, BIOS ID, CPU number, MAC and so on use Mathematica?
The only thing I could find very easily is the HWaddr of the network device that can be obtained by
SystemInformation["Network", "IPAddresses"]
- 112k
6
votes
Accepted
How to make the variables in $init.m$ not impact the autocompletion
Don't put symbols you don't want to show up in auto-completion into the Global` context. Use the same mechanism you would for a package.
...
- 232k
6
votes
6
votes
Accepted
Catching MachineUnderflow in Version 11.3
I just want to save this information from comments. @ilian mentioned in comments:
This command is simply not needed in 11.3 and later because what it accomplishes is now the default (and only) ...
6
votes
Accepted
How to build a tri-diagonal matrix
Try
n = 20;
M = Table[If[i == j, -(1 + 2/h^2), If[Abs[i - j] == 1, 1/h^2 + x1/(2 h), 0]], {i, 1, n}, {j, 1, n}]
or also
...
- 3,683
5
votes
Solving equation with multi variable matrix input
After correcting all errors and normalization to A, we have
...
- 41.1k
5
votes
variable K cannot be deleted
K is part of the System` context. You were removing symbols from the Global` context only, ...
- 232k
5
votes
Accepted
how to obtain all Messages for Mathematica build-in functions?
You could do something like this:
...
- 17k
5
votes
Where is the new System`ConvertersDump`$extensionMappings?
I haven't found extension mappings in the System context, but here's a way to build mappings of file extentions and file formats that shouldn't be affected by ...
- 4,613
4
votes
Accepted
Complete list of values for \$SystemID, \$OperatingSystem
The purpose of $OperatingSystem is to check what general OS you are on. You would check $OperaingSystem for tasks such as ...
- 232k
4
votes
Can one effectively edit a Front End Resource that is already loaded?
This is more comment than answer as you want in-memory modification, but it is possible to force the text resources to be reloaded. You do this with, e.g.,
...
- 46.6k
4
votes
How to obtain non-trivial solution?
Mathematica is correct. In general, there will only be the trivial solution.
You are trying so solve an equation $ M x = b $ with $ b= 0$. This will have a nontrivial solution if and only if $\mathrm{...
- 2,290
4
votes
Accepted
How to obtain numerical solutions of a system of two equations with two unknowns?
Clear["Global`*"]
EDIT: Corrected intervals in Solve
...
- 149k
3
votes
Choice of variables name affects the behavior of expression evaluation
They are the same expression, just simplified differently. You can verify by changing the b->x in the first:
...
- 68k
3
votes
Accepted
Newbie Issues with Solving & Plotting a System of equations
ph == 14 - poh;
poh == -log[ohc];
These are equalities, not assignments. Your Solve function is written correctly, but the ...
- 635
3
votes
Accepted
Composition of functions not working
You must use Symbolize of the built-in Notation` package to use Subscripts as symbols.
Note:...
- 41.5k
3
votes
Where is the new System`ConvertersDump`$extensionMappings?
By checking the output of
Export["a.txt", Export["a.txt",] // Trace] // SystemOpen
I find the variable
...
- 62.8k
2
votes
Where can I permanently modify $Path?
You could modify the global options in the options editor (Win.OS**Ctr + Shif + O**).
look up the
EvaluatorStartup
and put code
...
- 2,399
2
votes
Accepted
One inequality with two variables
A mathematical proof would be best, but Mathematica can provide some evidence against the statement that
...
- 23.6k
2
votes
Accepted
Solve says my system of equations has no solution
I think MMM is being ingenuous. Reduce returns a rather complicated expression with a lot of conditionals (24 of them). It turns out that the equation for ...
- 107k
2
votes
Accepted
How to put equations in Block or Module to return n values?
Don't put your definitions for other functions in your definition of w. Write your code like this:
...
- 107k
2
votes
Where does Mathematica get the value of Environment["PATH"] on newer version of OS X?
As noted in the second answer to the question you linked to, this is not entirely stable from version to version in OS X. That's under Apple's control, not ours. It also varies based on the ...
- 14k
Only top scored, non community-wiki answers of a minimum length are eligible