Questions tagged [assignment]

For questions relating to assignments to symbols, patterns, or expressions.

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Approximating the density of an arbitrary set using an arbitrary Folner Sequence of its superset [duplicate]

How do we use Programming to approximate this limit where is the density of in , is the Folner Sequence of , is an interval with , and . For more information, click on this link (replace G,X,i,g ...
128 views

Error Message when nothing should be evaluated

When I try to define this simple function getCoeff[SeriesData[_, _, coeff_, _, _, _]] := coeff[] I get an error: ...
34 views

ContourPlot a list of equations generated by the Table command

The first command below produces proper contour lines while the second command produces an empty plot. I would think that the two commands should produce the same output. What's going on? ...
26 views

Defining a function from an evaluated function stored in a variable

I have the evaluation of a function b, stored in appo. Now I want to define a new function f ...
47 views

Monte Carlo Method [duplicate]

How do you use a Monte Carlo method to approximate the area enclosed by the circle.
33 views

Mathematica: Remove argument from object with flat attribute

I have an object in mathematica with the attributes Flat and OneIdentity. I also defined the following substitutions: ...
59 views

Combining With, If and SetDelayed

I just noticed that With[{x = 1}, If[x == 0, 0, 1]] returns 1 (as I expected) but ...
39 views

Drop-down menu to globally change definition of a function t[x]?

If have a function t[x_] which is used extensively in a long notebook, but which has a variety of definitions, and which is used in a variety of ways. I'm looking ...
28 views

How to select certain numbers to assign a new value and others still keep same

For an array TestA={15,12,5,8,6}, I want to change the value of number greater than 10 into 0, as TestB={0,0,5,8,6}. When using "Select" command, I will lose some numbers. Thanks.
29 views

Vector shape and Dimensions

I think I have not understood clearly the difference between dimension and shape. I want to construct a vector remembering recurrence of the type : ...
32 views

Programmatically Inject Logical Vector into Manipulate Checkboxes or Vice-Versa

I am building a large Manipulate application with about 50-60 checkboxes through which the user can select entities to be drawn on a main canvas. The main drawing routine, called from within ...
59 views

Error in Assignment

I want to create a matrix with each element updated as per the formula, whose inputs are dependent on the location of element in the matrix. ...
29 views

In my StyleSheet, I would like to assign to the environment Subchapter the Key Alt+2 (via MenuCommandKey. However, this is ...
95 views

How to assign output of Last@Reap to a variable? [closed]

I would like to define a variable that equals the solution of a numerical equation. Usually something like smax=zmax/.FindRoot[Exp[-zmax/2]==2,{zmax,0}] would work. ...
42 views

Why does it fail to assign values to variable in Grid? [closed]

I have a grid such as the following, and want to assign the values in the second row to the variable in the first row, but it always fail, can you provide a solution? Thank you! ...
41 views

I am asserting a variable in Mathematica as Real yet it is not implementing it!

Element[\[Theta], Reals]; Ga = g; Gb = g*Exp[I*\[Theta]]; {{Conjugate[Gb], Ga}, {Ga, Gb}} I have a code as such for a matrix as given above. as ...
29 views

Assign a Derivate to a new fuction variable

I'm having a new problem. I'm trying to create a new function from a Derivate of another function, but i'm can't getting it. Someone could help me? I'm thinking that is something in the syntax of the ...
31 views

A question about a replacement of element of set

To begin with, I'm a poor English speaker, which means it would be hard to read to natives... I was trying to memorize mRNA codons with mathematica. ...
65 views

How to use an up-value assignment when all symbols are “too deep”?

I would like to make an up-value assignment such as a/:Conjugate[a[x]]a[x]+Conjugate[b[x]]b[x] = 1 or ...
56 views

Replace constant in summation function using replace or If or /

Hi i how do i replace constant for k in this summation. For following: Even 2*n Even replace k by a Even 2*n+1 Odd replace k by b Here is the code ...
54 views

Making a function definition where the right hand side is evaluated before the definition is saved [closed]

My question is about assigning the resulting expression after evaluation of a function. So what I want: FOCf[x, y] := D[f[x, y], x] such it immediately ...
140 views

Is it possible to set values for a list of variables using a for loop? [duplicate]

Let me preface this question by noting that this is a simple example meant to clarify what I am asking. The actual context in which I want to implement this involves associations containing hundreds ...
138 views

Scoping of pattern variables [duplicate]

I have run into a problematic behavior, and then came to find that it is a "possible issue" called out in the documentation, but I guess I am just baffled that this IS an issue, and am wondering why. ...
61 views

Why it is doing part assignment? [closed]

I am writing an algorithm and need to keep updating an association called "verticesAssoc". My algorithm ran perfectly at first. However now I want to use the same algorithm on another association "...
20 views

Seeing definitions of built-in functions [duplicate]

Possibly a very amateur question, so I'll apologise in advance. I'm reasonably new. I'm trying to write a Dot equivalent of ...
64 views

unexpected result from augmented assignment to association

Is the last of these results expected? If so, how? ...
176 views

Transferring DownValues

I have a code in which I define something like this: cc[1, 2] = 1; cc[2, 6] = 12; cc[3, 7] = 3; After some manipulation I define a sort of temporary variable ...
48 views

Reassignment of variables

Another quick question of mine. If I want to assign variables to be some arrays in parallel, I can use a construct like ...
81 views

Reassign a value to an array element

I have a very complex code in which I assign a value to an element of an array and then I reassign to it another one. A minimal example: ...
65 views

Evaluating the 1st argument of Set

I want to assign a certain value to an element of a tensor. This element is identified by an array obtained from some evaluations, so we fix it. Here i present an oversimplified core part of my code: ...
424 views

Tag Times in Null is Protected [closed]

I've some problems with the error mentioned in the title. Unfortunately, my code is full of subscripts so I'll show it in a photo. In this code the central aspect is to assign a scalar value to an ...
180 views

Assign a function within a function [duplicate]

What I'm doing wrong? 1st function works as expected but the 2nd one doesn't. What I want is to enter an algebraic expression and two numeric constants and get the same result as with the first ...
47 views

How to use a calculated expression on left-hand-side of an assignment?

Elementary question, I guess: I have a left-hand-side something like this: ...
55 views

Trouble with UpSet(Delayed) and IgnoringInactive

I'm having problems setting an upvalue for a symbol that is supposed to ignore Inactive: IgnoringInactive[f[g[x]]] ^:= match; ...
57 views

Hot to single out numeric values from NMaximize

I have some problem with NMaximize. The function NMaximize gives result like this NMaximize[f[x],x] {f[xmax] ,{x -> xmax}} I've read in various answers that ...
89 views

assignments within Manipulate

I have encountered unexpected behaviour when assigning variables in Manipulate. Consider an inverted parabola y[x_, c_] := -x^2 + c The following code finds the ...
64 views

Symbolic variable assignment

I looked around and didn't see this question on the forum, so my apologies in advance in case this has been answered here. My question can be concisely described by the following example: ...
92 views

How to assign values using nested Part[ ] expressions?

Why doesn't this work? Can I make it work? ...
106 views

How to 'unassign' variables used for PlotPoints, which subsequently print as e.g. ChartingPrivatepvar\$727158

I have a table of four insoluble equations, fceq, in terms of unassigned variables, Subscript[fc, i], Subscript[μ, i]. I am using contour plots to visualise ...
1k views

Can't understand one paragraph in Power Programming with Mathematica

In the chapter 7 of the Power Programming with Mathematica, there is a paragraph discussing the behavior of Set- functions: (page 205. (pdf version p. 224)) ...
34 views

Assigning eigenkets to particular eigenspace depending on eigenvalues of system inside a module

I am writing a module, in which the Observable and State is given, so I need to write a function/module QuantumMeasurement, that will return a state of the quantum system resulting from the ...
42 views

assigning numerical values to variable

I have a csv data file, has two columns of data. First column denotes time (t) and the corresponding value in the second column is flow rate (f). I would like to assign these values to an array f[t], ...
57 views

Assigning variables whilst in a context

When working in a context, I would like all variable assignments to happen on symbols in the new context. This doesn't normally happen. For example, ...
149 views

How to set parts of Associations “named with” SubValues

Parts of Associations can be set with the following syntax: as = <|"a" -> 10|> <|"a" -> 10|> as["b"] = 20; as ...
55 views

Writing a variable to file with its value, not its name [closed]

This is my first time ever posting a question about Mathematica anywhere, so please excuse my ignorance. I'm trying to save a ColorFunction to file, but can't get the variables to be written as ...
114 views

Generalization of the probability of union

hi How can I do for mathematics to expand this equation for any value of the variables i, j, k
465 views

Multiple variable assignment from a list

For example in Python, if we have a list of 3 elements, say ls = [1,2,3] and we want to assign a variable to each value (from left to right), one can do as follows: ...
65 views

Matrix as function manipulation

Consider matrix mat[x_] := {{1, 2}, {3, x}} with mat[x][] giving {1, 2} I wanna ...