Questions tagged [conditional]

Questions about programming or mathematical constructs that enable verification, selection, or branching behavior when one or more criteria are determined to be True.

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3
votes
1answer
170 views

Use of semi-colons in If[]

This is the code in Mathematica: h[x_] := (If[x > 5, Return[big]]; t = x^3; Return[t - 7]) I fully understand what the code does, with ...
0
votes
1answer
50 views

How can I apply If or Which in a multiple Line list?

I have a multiple Line list ...
1
vote
2answers
113 views

Choosing among Conditional Expressions in Solve

I am solving the following symbolic equation. The parameters are of certain ranges, which I specify using Assuming. However the solution presents a list of values, ...
2
votes
3answers
112 views

Identifying maximal element in a list with case distinctions

I need to create code that identifies the positions of all maximum elements of a list. I already know that if myList contains only numbers, I can do ...
0
votes
1answer
80 views

Using “if” to compare 2 expressions (Complex and real numbers)

Hello. I want to solve this cubic equation and compare the answers then I can assing the lower result to "VmL" and the greatest result to "VmG" but I have problems when the result is a complex number ...
5
votes
1answer
112 views

Check if a symbolic matrix is hermitian

I have a symbolic matrix: Potential = SparseArray[{Band[{1, 1}] -> V0/2, Band[{2, 1}] -> V0/4, Band[{1, 2}] -> V0/4}, {2*max + 1, 2*max + 1 }] ...
0
votes
1answer
79 views

Defined function doesn't plot correctly

I have defined a function that produces a single negative impulse spanning -b to -a and a positive impulse spanning ...
6
votes
1answer
97 views

Conditional rendering of items

Let's say I have a column to display and each of its items can be hidden separately. Question: Is there a way to make it work without re-rendering whole column whenever a particular item is hidden? ...
0
votes
0answers
45 views

How to use === with condition?

I have two expressions, and they are same when k is positive and x is non-zero real number. Below code gives me ...
4
votes
2answers
146 views

Apply function over a list only if list members satisfy multiple conditions

I want to apply a function to members of a list only if all the members of the list satisfy a set of conditions otherwise return a result of zero. For example for ...
7
votes
1answer
153 views

Checking what a function depends on

I'd like to define specific partial derivative operators that change based on if the passed expression is a function of, for example, x vs. ...
1
vote
1answer
57 views

How to select terms which contain certain letters?

I would like to select the term Subscript[Cos\[CapitalDelta], Subscript[p, B]] of expression ...
4
votes
6answers
756 views

How to avoid applying Cross to a single argument?

I am looking for the simplest way to avoid applying Cross to a single argument. ...
4
votes
1answer
120 views

Solve/Reduce not working on a function with a condition/domain restriction?

I'm working with a trigonometric function, so I thought it would be convenient to set a condition to restrict the domain so I wouldn't have to specify it in the solve function each time. Here is a ...
4
votes
2answers
1k views

Generate “nice” random matrix

I don't frequent this community so please give criticism if this is a poor question. I am trying to make a tool which generates a small (say, $4\times 4$) matrix with integer entries which has a "...
0
votes
1answer
289 views

If without else [closed]

The syntax for If is: If[condition, then, else] Which is the correct syntax for the case in which there is no ...
0
votes
1answer
126 views

How to test if a solution of NDSolve is positive

I want to solve a differential equation numerically and determine one of the parameters in the D.E. The goal is to determine $M$ such that the function goes asymptotically to zero or to put it in a ...
4
votes
1answer
156 views

Unevaluated Which

I have the following Code: ...
3
votes
2answers
112 views

Colour panel upon condition of an input field

I have something like a "mortgage calculator", and I now want to colour the panel depending on the inputs that the user has made in my input fields. This would be the code: ...
5
votes
1answer
479 views

How to split list into segments based on first element of sublist, and remove ineligible segments

I have a list that looks like this: ...
1
vote
0answers
252 views

Ternary diagram

I'd like to make a RegionPlot on a ternary diagram, meaning in a triangle where the axis are $x,y,z$, which are related by $x+y+z=1$. The RegionPlot would have as a condition $x^2+y^2<1$ for ...
4
votes
4answers
139 views

Find the value fluctuating in lists

Suppose that I have the following lists of entries, ...
1
vote
1answer
93 views

ParametricPlot3D coloring based on whether function located inside/outside of another parametric function

I have two parametric shapes: an inclined ring and an elliptic cone whose vertex lies along the x axis. ...
3
votes
2answers
149 views

Evaluation of a ConditionalExpression

I am using Mathematica and I have to define several expression containing a condition. For my purposes the ConditionalExpression syntax seems to be appropriate. But ...
1
vote
2answers
88 views

How to define a delayed function with 'If' condition? [closed]

Let us define a function f[x_]:=x^2, then I want to define a delayed function g[x_] such that ...
2
votes
2answers
80 views

Shorter code for an If statement testing a variety of matches

How can I shorten these two If expressions into one ...
6
votes
3answers
170 views

How to create a sublist of elements with a congruence relation

I generated a list made up of lists of four elements such as: n = {{49, 9, 9, 5}, {57, 13, 9, 5}, {81, 21, 13, 5}, {95, 19, 19, 7},...} I would like to create a ...
0
votes
0answers
58 views

How can I select the true expansion?

I have a series expansion which gives two results. Series[-(1/ Sqrt[-1 + x + x z1^2 \[Chi]^2]) , {x, 0, 1}] /. y -> x I want only the series which is true. ...
2
votes
3answers
95 views

Make the values of a function zero, when it becomes complex or indeterminate

I have a function like this: ...
9
votes
2answers
335 views

Finding the condition for root of a third degree polynomial

I've a third degree polynomial (in $s$): $$as^3+bs^2+cs+d\tag1$$ I need to find the roots of the polynomial, so I can use the code: ...
9
votes
1answer
112 views

JoinAcross datasets based on Equal and not on SameQ

JoinAcross will join keys if values are the same (SameQ==True) but not if there are equal. For example these two associations are not joined : ...
0
votes
2answers
206 views

Appending data in a if statement

I'm new to Mathematica, only installed it just now. I have some data in the following format. ...
0
votes
3answers
148 views

Minimize a solution

I have three points in a 3D space A(xa,ya,za) B(xb,yb,zb) C(xc,yc,zc) I would like to find the smallest sphere which pass A,<...
0
votes
1answer
138 views

“conditional” initial condition for pde

I'm trying to solve a set of coupled pde equations of functions C1[t,x], C2[t,x]. all works fine but I need to specify a conditional initial conditions of the form: ...
0
votes
1answer
75 views

Evaluate until a regexp match is satisfied

How do you express the computation that, given a list of regular expressions, perform a replacement until one of them is satisfied. For instance: ...
0
votes
0answers
38 views

How to carry out a different function based on weighted probabilities

I am looking to carry out a function based on weighted probabilities I have looked at using If[] and random numbers but ...
3
votes
4answers
2k views

How to define conditional function with Mathematica?

How to define conditional function $f(x,y)$ with the following result. If $x=1$ and $y=0$ then $f=77$, if $x=0$ and $y=1$, then $f=66$, if $x$ and $y$ are all other integer values then $f=0$. How to ...
2
votes
2answers
87 views

Why does conditional NExpectation fail for a multivariate distribution?

To give an example for a multiparametric distribution let us take a binormal distribution: ...
2
votes
2answers
49 views

behavior of functions with parameters inside arguments

I don't understand this behavior: why does Limit[z/(z - a), z -> 0] give zero and not a condition depending on a, provided it ...
0
votes
2answers
38 views

Reduce: number of available solutions changes and I want to pick the lowest

I have an equation that has no analytical solution and can have multiple roots. I am focusing on Real roots that are in the (0,1) interval. For example: ...
1
vote
1answer
89 views

Cases with condition vs Select inside Manipulate

I tried to plot integer points that fall into a 2D region that's dynamically changed. So I resort to Cases and Select, but ...
2
votes
1answer
83 views

Conditional Programming

I need help creating a function that takes 5 integer inputs and does the following: If exactly 2 or 3 of the first four inputs are not divisible by the last input I want the output to read “...
0
votes
2answers
118 views

Problems with If condition when Pochhammer symbols are zero

There is a formula for the hypergeometric ($_2F_1$) that expresses it as a sum of Pochhammer symbols, times something that reads $$_2F_1(a,b,c;x) = \sum_{i=0}^{\infty} \frac{(a)_i (b)_i}{(c)_i} \frac{...
-1
votes
1answer
84 views

Using `If` condition to replace columns of a matrix

I have two matrices: ...
1
vote
2answers
944 views

Define a function with a condition

I defined a function u[y]. ...
3
votes
4answers
1k views

Using “If” statement to change a list values

I have a question that would be pretty trivial in almost any other language but is giving me a massive headache in Mathematica. I am trying to construct an If statement check on one variable that I ...
0
votes
0answers
377 views

Can For loop be used with multiple conditions?

I am wondering if For could be used with multiple conditions (tests). For the simple example ...
6
votes
2answers
3k views

How to restrict the domain of a function

I realize this question has been asked many times, but I am fairly new at Mathematica and the other answers are very complex, and certainly too complicated for this simple code I am trying to write. ...
0
votes
0answers
46 views

How to pass var to Select[(#colunm == value) &] construct [duplicate]

I'm using a construct (more complex in fact as the value_ should take a list) to select some entries from an association with criteria: ...
0
votes
2answers
160 views

A simple code for conditional double summation?

I wrote a code as follows ...

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