Questions tagged [parameters]
The parameters tag has no usage guidance.
65
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Find the parameter in NDSolve giving the desired solution
I find myselef in choosing by hand the right parameter that let ParametricNDSolve return the desidered solution. I'm sure there is an easy alternative, but I can't ...
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1
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58
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2
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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 ...
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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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3
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269
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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 ...
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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 ...
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45
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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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Comparing parameter regimes workflow
I have some code that relies on some parameters. I pick a set of parameters, calculate some things, solve some differential equations then plot various things with the solution.
Ideally I'd like to ...
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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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81
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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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112
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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-...
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Problem with ParameterFitting:""The function value...is not a list of real numbers..."
I'm trying to use the data:
...
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65
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Restrict the domain of a function (and plot) it) when it depends on the value of a parameter
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 ...
- 107
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72
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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
...
- 151
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28
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Logarithmic NonlinearFit with 10 parameters? Is Not a Real Number
I am trying to fit a collection of data with a fairly complicated function, and have been running into some errors. I am very new mathematica user, and am not really sure where I am going.
This is my ...
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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 ...
- 2,147
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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 = \...
- 11
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3
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How to ask Mathematica to do the given operation for a set of parameters?
I have a set of numbers like this
s = {a, b, c, d, e, f, ..., g, h}
and I would like to ask Mathematica to do the following operation (to sum the subtractions of ...
user67849
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Find parameter distribution how i know any initial value i must put?
FindMaximum::eit: The algorithm does not
converge to the tolerance of _4.806217383937354`*^-6_ in _500_ iterations
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45
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How to pass a URL parameter to FormPage?
I'm trying to pass a parameter on a FormPage. I know that passing parameters on a APIFunction works, like:
https://wolframcloud.com/...?x=5&y=10
But, I see no ...
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32
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Solving equation for specified parameters
I have a long expression which depends of several parameters
...
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When i use findparameterdistribution parameters are diffient from in reasearch why? [duplicate]
This is Chen weibull distribution
...
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84
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Why does FindDistributionParameters[] fail to converge for this distribution? [closed]
During testing my code for calculate parameters
The following exception is thrown:
...
- 29
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97
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Trying to find values of two parameters that match the boundary conditions defined
I have been trying to solve for the values of two parameters that satisfy the boundary conditions set for a set of equations set. The below is the code.
...
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2
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68
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How to replace one parameter with multiple values
I am a beginner. I have a function with one parameter and I would like to replace a list of values that have names. I would like a result so that the names are not lost.
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175
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Automatic backup on Mathematica
When there’s a power outage and I’ve done a lot of work on Mathematica, I lose all the informations. Is there a setup on Mathematica to make an automatic backup. Knowing that on "wolfram cloud&...
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69
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Defining $f(x)=mx+b$ with $m,b$ separate versus `f[m_ ,b_ ,x_]:=mx+b`
Suppose I want to define a function $f(x)=mx+b$. And suppose I might want to change $m$ or $b$ later.
Specifically, suppose I initially want $m=-2,b=10$, but maybe will change these values later
Two ...
- 707
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2
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149
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Extracting the component distribution parameters from a mixed-normal distribution (for n > 2 normal)
I'm trying to extract the distribution parameters of the sub-distributions which comprise a mixed normal distribution.
I'll give my attempts so far.
First the simulated data:
...
- 2,291
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2
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269
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How to find explicit hyperplane in SupportVectorMachine
I am using the SupportVectorMachine classfier:
e.g., (* let me use Linear kernel for simplicity *)
...
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1
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197
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NDSolve: input a value for a parameter from a list of values
I have a parameter in an equation which has a different value at each step from a list of values calculated in a former NDSolve differential equation. While what I am trying to achieve is more ...
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65
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NDSolve and NIntegrate with parameters
I have a problem with a numeric computation. I should solve a numeric ODE and the rhs is a numeric parametric function that I find with several NIntegrate. I'd like ...
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81
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Find the condition under which an inequality holds
I've got an inequality of 8 non-negative parameters (arising from a 5x5 matrix) and would like to find a condition under which my inequality holds. The condition would be an inequality too of these ...
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202
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Verify an inequality of many parameters
I've got an inequality of 10 non-negative parameters (arising from a 5x5 matrix) and would like to verify whether it holds. I tried the following, which doesn't seem to work:
...
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Can you force Integrate[] to find a complete symbolic solution for all variables?
(As I've asked on the Math StackExchange and on a related previous question), I am interested in getting a complete symbolic solution to the integral of an expression with a lot of unassigned ...
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2
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281
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Unreliable parameters errors from NonlinearModelFit [closed]
Goodmorning everyone,
I'm trying to fit the following data
...
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111
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Minimize chi square fot non-linear fit
I recently started using Mathematica, so I have a question.
I would like to find the parameters of a non-linear function by minimizing the chi square. How could I do?
The function would be like this :
...
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Why do I keep getting these error messages?
I am trying to fit a parametric differential equation system to the data of the infection cases in Hungary. I keep getting the error messages:
ParametricNDSolveValue::ndcf: Repeated convergence ...
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Steady State case for differential equations
I need to write these equations in steady state form (time derivatives set to 0), and then substitute in values for the parameters (e,d,q,f). However, I don't understand how to do this as if I set the ...
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Parameter space for a theory [closed]
I was trying to learn to make plots of parameter spaces.
For example, if I have a theory with one free parameter
$$g(z)=\alpha(1+z)^2$$
I know that you can plot the function ass function of $z$, ...
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How to plot functions of multiple variables with multiple constraints as a function of just one variable
Essentially I would like to plot the solutions to the following equations in terms of only 2 of the variables included: I have the following simultaneous equations:
...
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String arguments break optional argument default values? [duplicate]
Following a tip in this post, I use string parameters to label my functions. For example, instead of f[x]:=x^2, I use ...
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72
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Problem with solving a system of differential equations within Manipulate
I'm triing to do this commands:
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249
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Pick out elements from a list of lists using criteria
Consider a list of lists in this form (with a shape $ m \times n \times 3 $):
...
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Mathematica slow at estimating vector autoregressive model parameters
I have been trying to obtain VAR model parameters using EstimatedProcess and FindProcessParameters. It seems to take a very long time as soon as I have more than 6 or 7 time series and lag length >2.
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417
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Solve an ODE with parameters in a boundary condition
Consider the ODE:
ode = y''''[x] - 2*k^2*y''[x] + k^4*y[x] == I*k*a*((2*x - x^2 - c)*(y''[x] - k^2*y[x]) + 2*y[x]);
in which a...
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NDSolve issue, potential singularity or stiff system
I have the following parameters, equations, and NDSolve solution set up as such:
...
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Nonlinear differential equation with unknown parameter and integral form boundary condition
I'm trying to solve numerically a non-linear problem in order to determine the velocity field ($U$) and the film thickness ($h$) of a non-Newtonian fluid over an inclined plane. The equations are,
$$\...
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Big Confidence Interval for seemingly rather accurate variable, NonLinearModelFit [closed]
I used NonLinearModelFit to fit a function of the form a*Abs(Cos(x))^b to a set of 5 points, that each have a uncertainty. My ...
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What is wrong with this input? [closed]
I've followed the examples from the introduction to mathematica for math students:
https://www.wolfram.com/language/fast-introduction-for-math-students/en/more-plots-in-2d/
...