# Questions tagged [parameters]

The tag has no usage guidance.

95 questions
Filter by
Sorted by
Tagged with
66 views

### Find the condition under which an inequality is satisfied

I need to find the conditions among the variables under which the inequality est-tru>0 holds. ...
62 views

### How can I calculate P-Value for a custom distribution?

I used DistributionFitTest but it works only with a defined distribution. This is the distribution that I used: ...
92 views

### SIR Parameter Estimation in Mathematica

All infected individuals go through an incubation period, which lasts on average for 4 days. During this time, individuals are not infectious, nor do they have any excess mortality risk. All infected ...
112 views

...
130 views

### Optimize parameters for differential equations

I have differential equations f11, f12, f21, and f22 with respect to t with parameters A and B. I've defined and solved these equations using NDSolve in Mathematica as follows: ...
126 views

### How to define function that returns another function?

I'm new to Mathematica and I have an issue: I'm trying to define a function that accepts as parameter another function with parameter X and then returns a function also with parameter X. Input: ...
1 vote
142 views

### How to check whether a function parameter is another function?

How can I check if a function parameter is another function defined with := f[n_] := n^2+1 g[fun_, n_] := fun[n] g[f, 3]
119 views

### Solve computes discontinuous eigenvalues of parameter-dependent matrix

So I have a family of unitary matrices $m(x,y)$, which depend on two parameters $x,y \in [0, 2 \pi)$. Its eigenvalues should be continuous in $(x,y)$. Since $m(x,y)$ is a unitary matrix, its ...
1 vote
32 views

### PlotLegends parameter with subscript and multiple of other parameter in Mathematica

PlotLegends -> LineLegend[{Style[Subscript[ω, i] t == 0, Black]] When I use this command in Mathematica 13.2, I get ...
81 views

### Is there a function which checks the validity of a string to be used as argument to RegularExpression?

Is there a function which checks the validity of a string to be used as argument to RegularExpression? Composing regular expressions is not an easy task. In ...
41 views

### How to attribute the right encoding for PointValuePlot

in the following program ...
1 vote
68 views

### How can I write a function definition which gets another function as parameter whether the parameters of the function match a pattern?

One can write functions which depend on the type of actual parameter before they are actually called. E.g.: ...
1 vote
37 views

...
199 views

### Plotting an inequality over the range of a parameter

I have a simple inequality, $$x+\cos(\theta)\, y > 0$$ and I'd like to plot the region in $x,y$ space which satisfies this inequality for all values of the angle $\theta$. I'm trying to do this ...
33 views

### Defining parameter as function without losing properties of the derivative

I have built a code that is later on solved dynamically depending on values I set using Manipulate while plotting. However, I came across a problem I cannot resolve. So, I defined ...
1 vote
50 views

### Calculating eigenvalues and solving inequalities with parameters

I would like to calculate b in terms of c and a, in order to satisfy the following conditions: ...
41 views

...
62 views

### ParametricNDSolve with 2 parameters displays unexpected behavior, crosschecked with 1-parametric version of the same system

I apologize in advance for posting some lengthy code, I tried to tackle this with a simplified question yesterday here but once I implemented the suggested answer by @march deeper issues arose. I am ...
1 vote
50 views

### Using NSolve after ParametricNDSolve to find the value of one parameter over a range of values of the other parameter and at a specific time

I am new to Mathematica, so excuse me if this is trivial. I could not find anything similar by browsing questions or the wiki. I am working with a long set of ODEs but currently my problem can be ...
1 vote
70 views

### NestWhile question, ensuring a function is repeatedly applied to a newly set input-value

Problem: I need to ensure that a function which is repeatedly called in NestWhile correctly uses a newly computed input on its next call. I will give the context while omitting parts of the code (...
129 views

...
46 views

### find maximum don't work with me i don' know why? [closed]

i have log function like this and i want to find maximum for it the log function like this ...
1 vote
I have a recursive expression defined as $$h_u= (1-a)(1-b) h_{u-1} + \sum_{k=2}^{u-1} (1-a) b h_{u-1-k} - \sum_{k=2}^{u} h_{u-k} - \sum_{k=1}^{u+1} \Lambda_{u,k}$$ where $\Lambda_{u,k} = \sum_{m=u-k+... 2 votes 1 answer 95 views ### Evaluate a double sum using Mathematica I am evaluating using Mathematica, the double sum$\sum_{u=0}^\infty \lbrace \sum_{k= u+1}^{u+y}[\dfrac{(1-a)}{4} (3/4)^k + 3a[(\dfrac{1}{2})^{k-1} - (\dfrac{3}{4})^{k-1} ]\rbrace $, where$'a' $is a ... 0 votes 1 answer 84 views ### I have a problem in log likelihood which I wrote for custom distribution I have a custom distribution and data as follows ... 0 votes 0 answers 21 views ### Estimate parameters from random samples drawn from a copula distribution [duplicate] I defined a copula distribution as follows: ... 0 votes 1 answer 72 views ### what is wrong in my code for calculate parameters bivariate distribution? data is i,j as x, y as in pic ... 0 votes 1 answer 101 views ### How to find maximum likelihood parameter estimates for a custom bivariate distribution? this is univariate distribution ... 2 votes 2 answers 109 views ### What's wrong in my custom distribution? i want to write this function ... 1 vote 2 answers 98 views ### How to assign table parameters to use it many times I'm using two nested Table to generate data which depend on two parameters, let's say it is temperature and pressure, many times in my code. When I change the temp ... 0 votes 2 answers 94 views ### How to take the derivative with respect to a function with more than one variable? I have a function that includes another function inside. I want to know the derivative at every point x. I have spent a lot of time trying to figure out how to do this, but I am very lost. I have ... 4 votes 1 answer 577 views ### My model has not finished evaluating in more than a day so can't test if it works, what is wrong with it? Hello I have this modified monocentric city model that I have been working on for a while. Sorry for the long post, I wanted to add the whole code, because it's all connected. My suspicion is that it ... 1 vote 1 answer 146 views ### Finding fit parameters for a 2-dimensional matrix of data if the value of some parameters depend on the row and others on the column I have some 2-dimensional data of dimension n x m that I suspect has the following structure: ... 1 vote 1 answer 200 views ### Find the parameter in NDSolve giving the desired solution EDIT: I've edited many times because the system gives errors when the body is modified all at once. I've simplified the problem. The simplification consists of having reduced the number of parameters ... 0 votes 1 answer 67 views ### NonlinearFit with series coefficients I have a set of data: ... -1 votes 2 answers 97 views ### Plotting the parameter space corresponding to a solvable equation I am considering a function$f(T, c_1, c_2)$for which I would like to plot the region in the$c_1$and$c_2$parameter space that corresponds to the values of$c_1$and$c_2$such that$f(T)=0$has a ... 1 vote 2 answers 108 views ### How to organise definitions that contain named parameters? I have lots of definitions of (usually numeric) quantities that depend on parameters; they're mostly matrices (in the actual code, there are many more definitions): ... 0 votes 1 answer 191 views ### How do I calculate Mean Squared Error of parameters alpha and beta? [closed] ... 3 votes 2 answers 334 views ### Problem with solving a linear ODE with a parameter I have been struggling with the following ode for several weeks, but I fail to solve it. So I post this question and my attempts and expect someone here could give some suggestions. First, define an ... -1 votes 1 answer 67 views ### Integrate and InverseFunction I solve an easy example to check that Mathematica can understand the difference between ArcTan and ArcTanh but as you see here I can't get Arctanh??!! Even I don't know why the inverse function is not ... 1 vote 0 answers 99 views ### How to fix a parameter in SolveAlways In expression: SolveAlways[f1(a)+f2(b)x+f3(c)x^2+f4(d)x^3==f5(d)x^2+f6(e),x] Functions fi are known. How do I tell mathematica that d is a fixed constant?. I want ... 1 vote 3 answers 247 views ### How to specify the domain of a parameter? There is a similar post: How to specify the domain of a variable?, but it doesn't work well for me. I want to evaluate the integral below, with a parameter$\gamma$. The result is obviously different ... 2 votes 1 answer 95 views ### Table of surface Parametric draw I'm trying to reproduce this kind of graph for a spherical cap, with different span ratios. I tried with this: ... 0 votes 0 answers 138 views ### Solve Differential Equation with Boundary Conditions (lengthy equation) I have a lengthy equation to be substitute into a differential equation. I used DSolve to generate the output. However, it took me more than 3 hours and it still running. The DE is the convective-... 1 vote 3 answers 83 views ### Problem with ParameterFitting:""The function value...is not a list of real numbers..." I'm trying to use the data: ... 0 votes 1 answer 180 views ### Restrict the domain of a function (and plot) it) when it depends on the value of a parameter [closed] I know similar questions have been asked, but I am very new at Mathematica and other questions/answers are quite complex and do not suit the code I want to write. I want to restrict the domain of the ... 0 votes 1 answer 222 views ### Solve in parametric equations in term of a set of parameters I am not sure the title is right but let me explain. I have the relations ... 0 votes 2 answers 55 views ### How to make the third parameter optional and adding some condition? I have a function as follows. The function has 3 parameters. Now I would like to make the third parameter i optional. So you call call it like ... 1 vote 1 answer 122 views ### How to initiate a matrix with indexed parameters [closed] I couldn't find it in the documentation, so I'm posting it here. I want to create two by two matrices as follows:$\$ `W = \begin{bmatrix}w_{11} & w_{12} \\ w_{21} & w_{22} \end{bmatrix}, V = \... 