Questions tagged [parameters]
The parameters tag has no usage guidance.
102
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How do #1 and #2 work in a function defined by 2 variables?
Can someone please explain the function of #1 and #2 in a pure random function of two variables?
For example, if I had something ...
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85
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Elegant way with minimal redundancy for handling function parameters and starting values when plotting and fitting
The following code shows how I handle making up a function, finding starting values, fitting and plotting. You see that handling the parameter names, starting values, plotting values is highly ...
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54
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Solving and plotting roots of a non polynomial equation with parameters
In Mathematica 12, I want to find the roots r of this equation in terms of the parameters M and Q, then plot r versus Q for some values of M.
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73
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Expression as parameter to function that evaluates it, best way to do it?
I need a function fSum that computes the angular sum for some expression, like this:
fSum[3 Sin[2 x], 0, 2 π]
Or from a predefined function, like this:
f[x] = 2 Sin[3 x];
fSum[f, 0, 2 π]
Or plots it ...
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2
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Problem with $ sign in temporary function parameter
I am having a problem with $ sign in the name of a parameter to a temporary function. The functions I have should compute the angular sum (or turning angle) for some expression generated by function <...
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416
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How to plot a surface given implicitly by 3 equations in 5 coordinate variables?
I have 3 implicit equations in 5 variables: $f_1(S, y_h, y_d, x_h, J)=0$, $f_2(S, y_h, y_d, x_h, J)=0$, and $f_3(S, y_h, y_d, x_h, J)=0$. These equations determine a 3D surface in $S-y_h-y_d$ ...
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63
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Problems with Solve. Only works for specific parameters. Solve function do not "start"
I have the following problem I want to solve the following equalities.
My used code:
...
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88
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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.
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- 496
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84
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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:
...
- 59
2
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1
answer
149
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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 ...
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137
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2
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150
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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:
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162
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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:
...
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153
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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]
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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 ...
- 103
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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 ...
2
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1
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91
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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 ...
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47
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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.:
...
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37
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219
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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 ...
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33
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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 ...
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59
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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:
...
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46
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81
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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 ...
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68
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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 ...
- 23
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78
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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 (...
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197
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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
...
- 369
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104
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Plot of a recursive expression having a parameter
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+...
- 53
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115
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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 ...
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90
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I have a problem in log likelihood which I wrote for custom distribution
I have a custom distribution and data as follows
...
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23
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Estimate parameters from random samples drawn from a copula distribution [duplicate]
I defined a copula distribution as follows:
...
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73
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what is wrong in my code for calculate parameters bivariate distribution?
data is i,j as x, y as in pic
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115
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How to find maximum likelihood parameter estimates for a custom bivariate distribution?
this is univariate distribution
...
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119
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100
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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 ...
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115
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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 ...
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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 ...
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212
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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:
...
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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 ...
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122
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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 ...
- 109
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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):
...
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289
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3
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390
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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 ...
- 1,229
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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 ...
- 153
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122
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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 ...
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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 ...
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102
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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:
...
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