# 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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36 views

### Trouble implementing switching hybrid system with NDSolve

I'm trying to use NDSolve to simulate a hybrid nonlinear system that switches between different linear behaviors based on states and inputs (i.e. switching from one linear behavior to another) which ...
125 views

### Pattern matching vs. condition in a function

I'm trying to learn stuff from pattern matching but I found sometimes pattern matching does not work as I expected. Could anyone explain why the below outputs are not same? Thank you. And could anyone ...
31 views

### How to find clear solution for iterative problem by condition $<v_k ,v_n>=0$ If $k!=n$

I want to find x[n] by v[n] values without x[n] in solution by iterative below problem: <...
69 views

### A simpler way of identifying which elements of Tuples[{0,1,2,3},6] multiply with each of my codewords to give zero?

So I have a list of codewords. The codewords have length 64, so there are 64 codewords in my code. My code is over an alphabet of 4 (the code can be thought of as having four elements $0,1,2,3$ and ...
45 views

### Creating an If function for the probabilities of the classes of images after using NetTrain

So I have 3 Classes the model can output after veiwing an image, at the moment it has a 70% accuracy, however this is not an issue as the plan is unless it's 85%+ sure on the Probability of the class ...
156 views

### How to check if at least one ordering of the given row matches one of the rows of a table?

Consider some list of elements ...
215 views

### How to check if the given row matches one of the rows of a table?

Consider some table tabb = RandomInteger[{0, 4}, {5, 4}] and a row row = RandomInteger[{0, 4}, 4] How to check if ...
1 vote
95 views

### Can you recover the original vectors that, when summed together, achieved a particular criteria

I am wondering if it is possible to take the binary strings of length $3$ (tuples) whose sums have weight $2$ (i.e they have $2$ non-zero entries)(binary case, meaning they have two $1$'s entries) u ...
44 views

### Identify a condition among variables that satisfy an inequality

I have a symbolic function that produces the output a = (1 - e - mu/n) Log[(1 - e - mu/n)/(1 - mu/n)] + (e + mu/n) Log[((e + mu/n) n)/mu] If I substitute ...
272 views

### Confused about If statement [closed]

I have this simple test code: n1 = 0; n2 = 0; m = 0; If[n1 == 0, n2 == 1] which evaluates as False, as it should. However, if I do: ...
107 views

### SetDelayed assignment not producing expected result when using ReplaceAll

In Mathematica, I am surprised that the following code does not do what I expect (what I expect is in comments after each evaluation). The problem seems to be due to the fact that when I define test ...
81 views

### Adapt elements in the list, condition by condition

Could you give me some advice? Suppose I have the following list. box[1,1]={{4.4, {1,1}, {a}}, {1.5, {1,1}, {a}}, {10.8, {2,1}, {3a}}, {10, {1, 3}, {3a}}} I want ...
1 vote
55 views

### Redundant cases from Sum

I am new to Mathematica. I would like to understand why Mathematica returns redundant cases, and whether it is possible to simplify them to the generic case $(n>1)$ that covers everything $(n\ge0)$....
685 views

### Make a list of the first 100 primes, keeping only ones whose last digit is less than 3 [closed]

This is a question from an "Elementary Introduction to the Wolfram Language" Section 28: Tests and Conditionals. We are asked to "Make a list of the first 100 primes, keeping only ones ...
98 views

### Condition inside pure function

Why condition /; not work inside pure function? Suppose we have: ...
104 views

### Compute the area of the union of the intersections of two conditions

I have four conditions over the two-dimensional domain $x,y\in[a,b]$. I want to use NIntegrate to compute the area of the union of the intersection of the two ...
41 views

### Optimization of conditions applying

Let we have some data generator, e.g. lazy tuples or permutations. I need to select data by some conditions cond1, cond2, …, up to 5-6 conditions. All of them need ...
1 vote
372 views

### Parallelize a "For" cycle

I'm trying to parallelize a simple routine inside a "for" loop. Essentially, I need to compute the roots of a function $f(x)$ that depends on the discrete parameters $d$ and $R_0$. However, ...
1 vote
58 views

### Weird behavior of Which with lists [closed]

To demonstrate my problem, let's create a little function: ...
137 views

### Convert list of conditional expressions to list

I have a long list of items of the form ...
60 views

### Efficient and compact replacement for Association in the following case

Consider the following association: ...
76 views

### How to minimize computational time in an if condition?

I have a code as below: ...
318 views

### Why does Select not work here?

Why does this not work? It returns empty while I expect the first two elements are selected. ...
157 views

### Generate all adjacency matrices of size $n=4$ s.t. $a_{ij}\neq a_{ij}$ and $a_{ii}==0$

I want to generate a list of adjacency matrices of size $n=4$ s.t. The diagonal is zero: $a_{ii}=0$ for all $i\in\lbrace 1,2,...,n\rbrace$ There are no 2-cyles, i.e. if $a_{ij}==1$, then $a_{ji}==0$ ...
117 views

### How to discard the repeating elements of a list [closed]

Lets say there is a random list of expressions : a={Sin[x], Sin[3 x], Sin[4 x], Sin[x], Sin[4 x], Sin[x], Sin [5 x], Sin[3 x], Sin[5 x]} Plot[{a}, {x, 0, 2 Pi}] ...
1 vote
90 views

### Selecting only one out of many: Differential equation

I have the following code: ...
117 views

### Selecting the specific values from a table and saving in a table:

I have the following code: ...
47 views

### Preventing Evaluation of Body of Manipulate

Overall, I am looking for a way to prevent the evaluation of the body of Manipulate until the controls meet a certain condition. For example, consider the following....
122 views

### The fastest and most scalable way to write a nested loop

The problem is to find the weights {w1,w2,w3,w4} that satisfy the condition. Which is the fastest and most scalable way (e.g. for 10000 weights) to write this ...
263 views

### How to select elements from a list of pairs based on first element belonging to a different list?

This is my very first question and I really appreciate this ability and thankful the community. I have two lists and need to select only those pairs from the first list, first element of which is ...
98 views

### Is there any alternative for conditional plot that gives a more precise result in a shorter time?

I have the given function $Func$ and want to have a plot of those domains where $-3\leq Func\leq 3$ in precise details. I am using ...
98 views

### How to plot multiple functions with conditions that assign values of some of them to be greater than the others?

i am trying to plot multiple functions in mathematica but i would like to do this in such a way that the values of two of my functions are always greater than the other two. my functions are: ...
81 views

### How to speedup comparison in the following example?

I have the following problem: I would like to generate random values of some variable $z$ obeying some distribution, but simultaneously within the interval zmin<...
185 views

### Creating a cycle with conditions

I would like to arrange a gift exchange between 5 people, Alice, Bob, Carl, Danny, and Ellen, and I would like the gifts to be passed in a randomly created cycle (B->C->A->D->E->B), for ...
120 views

### Removing "spikes" in data

Imagine I have a data set which gives me the following ListLinePlot Is it possible to define a function over the data set that removes the "spikes" ...
105 views

### Check the existence of roots based on parameters

I have a function which has one variable $r$ and two parameters $M,\lambda$. Whether or not the function has roots, depend on the parameters $M,\lambda$. I want to obtain a parameter space such that ...
81 views

1 vote
74 views

### Table mix with If function [closed]

Anyone could explain to me which problem is? after running the function "Table" combining with "If" as below, but the result is not a value instead. ...
121 views

### Unexpected behaviour of Condition with Cases/MatchQ?

When using the unsorted version of Complement in this question I met the following unexpected result, ...