Questions tagged [clear]
Clearing symbol values, removing symbols from memory and general garbage collection.
53
questions
1
vote
2answers
93 views
'Do' loop acting on a global variable
I need a code that will allow me to alter a matrix (a global variable) iteratively using a function update (which depends on ...
0
votes
0answers
65 views
Question about Clear function
I have a script starting with Clear ["r*", "data*", "file*"]. Does this clear all variables starting with "r" or "data"or "file"? Also, I ...
1
vote
1answer
45 views
Setting a function equal to another function then Clearing the latter
I have a loop in which several values of a function are computed, depending on the values for that function that were computed in the previous iteration of the loop. This could be implemented ...
10
votes
1answer
233 views
How to clear all definitions matching f[1, …] but not f[2, …]?
I would like to clear all definitions of the form f[1,...] in such a way that f[2,...] remain unaffected.
The two methods I know ...
6
votes
1answer
75 views
Clearing ::usage message
After having assigned the usage message to f using
ClearAll@f;
f::usage=ToString@RandomInteger@{10^10,10^11};
the ...
1
vote
1answer
81 views
How to clear all variables? [closed]
I have noticed that the old trick of using:
ClearAll["Global`*"]
does not appear to work anymore. It does not clear the values of any of my variables. I assume ...
4
votes
4answers
159 views
Is it possible to create lookups on temporary symbols that still allow the symbols to be automatically removed?
Is there some way to create lookups keyed on Temporary symbols that somehow avoid the referencing of the Temporary symbols, ...
1
vote
0answers
163 views
How to clear all subscripted variables? [duplicate]
I have the following variable:
Subscript[n, 0 ] = 12 (\[Sigma] L^2)/(e h^2)
If I now do:
ClearAll["Global`*"]
And then ...
18
votes
2answers
610 views
Different strategies to get a clean Kernel. Quit, Exit, ClearAll, Remove, CleanSlate?
Often new users face problems with lingering definitions that, if unaware, may cause unexpected and frustrating behaviour.
There are several answers that illustrate different aspects of the solution, ...
2
votes
2answers
356 views
Clear variables inside Module
I have a function that uses Module. The function takes as input a .csv that can have as many columns as it wishes to, and it ...
4
votes
1answer
90 views
ThrowAway Environment and Scoping
I want to be able to Get a .wl file. Run some functions (who will do their job working on some separate files that are being written away). And then return to some clean slate so that I can repeat ...
-1
votes
1answer
158 views
meaning of variable equal dot [closed]
I came across a program which I have written in a simplified form.
For[i=1,i<100, i=i+1;
func = a x^i;
func=.
];
What is purpose of "func=."?
0
votes
2answers
208 views
How to 'unassign' variables used for PlotPoints, which subsequently print as e.g. Charting`Private`pvar$727158
I have a table of four insoluble equations, fceq, in terms of unassigned variables,
Subscript[fc, i], Subscript[Ī¼, i].
I am using contour plots to visualise ...
10
votes
1answer
86 views
Why ClearAll[n] does not clear effect of NumericQ[n]=True
To solve some PDE, I have to set NumericQ[n]=True on some symbol to get a solution, else Mathematica will not solve it.
When I tried ...
4
votes
3answers
127 views
Apply Clear puzzle
This is OK
foo=1; bar=2;
Clear[foo,bar]
But this is not
foo=1; bar=2;
Clear@@{foo,bar}
Clear::ssym: 1 is not a symbol.
...
1
vote
0answers
40 views
Is ClearAttributes built-in functon work in current cell only?
I have a question. Is ClearAttributes the built-in functon work in current cell only? This is my code:
In first cell:
Set[a, 6]
In second cell:
...
5
votes
1answer
175 views
Clear a symbol from the kernel
I have a code that works over lists like
S0; (*initial list*)
S1=f[S0];
S2=g[S1];
S3=f[S2];
S4=f[S3];
.
.
.
where f and ...
1
vote
1answer
158 views
Is it possible to Clear all variables defined in a given cell?
Suppose I defined a number of variables in a cell, in the Notebook interface. I know the number of this cell (In[296], for example). Is there a way to clear all the ...
3
votes
2answers
66 views
ClearAll except a data table
How can I ClearAll variables and tables, except a table of data? Suppose the data table is WRR.
...
0
votes
1answer
96 views
clear value from a bunch of symbols
I have a bunch of symbols which are collected as a list inside a variable within a bit of code e.g.
a=1;b=2;
par={a,b};
I want to clear the values of both ...
35
votes
2answers
989 views
How do I disable the stack tracing feature in Mathematica 11?
Bug was introduced in 11.0 and persisting through 11.1
It looks like the Mathematica 11 stack tracing feature (see red ellipsis in front of any warning message) prevents the garbage collector from ...
0
votes
0answers
88 views
Calling Clear within a function [duplicate]
I want to create a function that when it is called clears the value of a parameter.
For example I want to keep the value of a parameter and then clear its valueby calling a function:
...
31
votes
3answers
731 views
Why does removing a function and defining it on the same line not work?
Why do the two pieces of code below yield rather different results? The only difference is that in the first one the function definition is in the same line as the ...
3
votes
1answer
413 views
How to “clear” the downvalues of a subscripted variable?
I have a function that sets certain subscripts of the symbol aa as in the following example:
...
0
votes
0answers
43 views
Deleting variable assignments in a sub-notebook which is called from my main notebook
I have two notebooks; one main notebook which calls another notebook several times in a loop. I want to delete the assignments of variables in the sub-notebook which is called from the main one.
...
14
votes
2answers
590 views
Good clearing practices
I have been using Mathematica for about 2 years and I'm pretty ok to write and optimize my code. Wanting to improve my practice, I often look at code examples. However, I can not determine if there is ...
16
votes
2answers
333 views
Global context seems to be shared between kernels when using Clear?
I am trying to understand the following behaviour, and determine if it's a bug in Mathematica 10. I am using Mathematica 10.3, and can't reproduce this behaviour under Mathematica 9. The test outlined ...
4
votes
1answer
260 views
Error given by the Clear function
I'm trying to clear out some variables that I've previously used, so that I can use them again. I tried this in a different notebook and it worked, however, now, a command like :
...
3
votes
0answers
44 views
Context is not clearable and does not reload [closed]
I'm just going crazy with Mathematica Contexts as they absolute do not work as intended.
Simple Example:
Begin["TEST`"]
Hello[s_]:=s
Bye[s_]:=s
End[]
Now using ...
9
votes
2answers
21k views
How to clear everything in Mathematica? [duplicate]
I am a new user. According to a documentation,
Clear["context`*"] clears all symbols in a particular context.
I want to clear everything (functions, variables, etc..)
After I use the above command, ...
2
votes
2answers
176 views
Partial reload of definitions from package
In order to keep my code modular, I have defined some functions in "Foo.wl" file, which I source with Needs["Foo`"].
When I modify a single function in Foo, I quit ...
2
votes
1answer
1k views
How to Clear derivative definitions?
I can't find a Clear or ClearAll command that gets rid of Derivative definitions I created. this code:
...
1
vote
1answer
142 views
How to be sure I've cleaned up all prior definitions and assignments [duplicate]
Is there any general way besides restarting the kernel to make sure that nothing I've done earlier in a session will affect code I want to run now?
One book suggested running ...
7
votes
1answer
264 views
Garbage collection for memoized functions on subkernels
I have a top-level function which operates on some data:
findBestIntegers[data_]:=ParallelMap[optimize,data]
which makes parallelized calls to an optimization ...
3
votes
1answer
4k views
Why my differential equations become True? [duplicate]
I've been trying to solve a system of nonlinear differential equation, but the conditions are a bit weird.
Two of the differentials equate to the same equation, but have different boundary ...
1
vote
1answer
106 views
Do I need to clear all definitions whenever I experiment with new parameter values?
Do I have to clear all my definitions whenever I experiment with different parameter values for my model? For example, I have a simple model as follows:
...
4
votes
2answers
227 views
Unset while running recursion
I am trying to run a recursive definition while at the same time clearing previously found values, so my memory is not completely consumed. I found this: How to clear parts of a memoized function? ...
21
votes
2answers
6k views
Error entering equation in DSolve
I entered a command incorrectly as follows:
DSolve[{y'[x]=y[x]},y[x],x]
I am now experiencing:
...
5
votes
1answer
338 views
Remove Removed From Output
How might I remove Removed[..] symbols from the output of an expression?
For example
Clear[b]; b := Sin[a + a]; Remove[a];
b
...
9
votes
1answer
3k views
Clear and Unset doesn't free memory
Example: Try this example only if you have > 4G ram
d = 2000;
f[x_, y_, d_] =
Sum[Subscript[a, i, j]*x^i*y^j,
{i, 0, d - 1}, {j, 0, d - i}];
Then
...
8
votes
2answers
491 views
ClearAll[“Global`*”] stops working with Context set to 'unique to this Notebook'
I just changed my default notebook context to 'unique to this Notebook' so that variables don't roll across numerous open notebooks. Doing this, however, made the command ClearAll["Global*"] stop ...
10
votes
1answer
2k views
ClearAll just for current notebook
So in my search to fine tune Mathematica to what works for me, I found a nice setting that helps separate variable declaration between notebooks. Under Global Preferences, searching for CellContext ...
34
votes
3answers
2k views
How to clear parts of a memoized function?
I have a function of two variables, e.g.:
f[a_, b_] := f[a, b] = something f[a - 1, b - 1] etc
With the above code I used the concept of memoization to speed up ...
10
votes
2answers
2k views
How to clear just variables defined in one notebook?
I'm trying to set up some notebooks so that I have one "seed" notebook that defines all my values globally when I run it. I have three other notebooks that take these values and run with them to do ...
18
votes
1answer
743 views
Is it possible to Clear all variables (but not functions)?
I have written a Mathematica script in which I define functions and variables. Here is a vastly simplified example:
...
21
votes
6answers
6k views
How to clear all variables except one?
I have a lot of variables: $a,b,c,d, \ldots $
I want to clear the values of all of them except $b$. It's really lengthy to write
Clear[a];
Clear[c];
...
Is ...
23
votes
4answers
2k views
Elegant manipulation of the variables list
I have a list of global variables (some of them are indexed variables), for example:
varsH = Hold[U0[1], U0[2], B0, V0[1], V0[2]]
Or (if it is easier to handle) ...
40
votes
1answer
2k views
What is the story with Removed symbols?
The system function Remove evidently exists primarily to turn a fatal problem into an annoying one, by giving the user a (rather blunt) instrument with which to ...
4
votes
2answers
6k views
How do I clear all variables with subscripts? [duplicate]
Possible Duplicate:
Clear complains that a variable is not a symbol or a string?
Clear["Global*"]` Works for most variables, however if i do something like
$ \...
19
votes
2answers
3k views
How to unload automatically loaded packages?
I know that this has been discussed here (How do I clear all user defined symbols?), but my case is somewhat different. How does one unload packages during runtime that were loaded with the start of ...
