# Tagged Questions

Clearing symbol values, removing symbols from memory and general garbage collection.

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### 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) ...
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### How do I clear all user defined symbols?

Is there some way to do this other than going to Evaluation -> Quit kernel and firing a new one up?
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### Error entering equation in DSolve

I entered a command incorrectly as follows: DSolve[{y'[x]=y[x]},y[x],x] I am now experiencing: ...
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### Clear complains that a subscripted variable is not a symbol or a string?

Here's a small listing where I've used EscqEsc to typeset θ in the notebook: ...
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### Is there a way to separate variables between multiple notebooks?

I often correct homework by checking the calculations in Mathematica. Sometimes you would like to have two solutions open at once. However often defined symbols such as ...
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### 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 ...
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### 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 ...
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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 ...
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### 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 ...
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### 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 ...
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### 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 ...
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### 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, ...