Linked Questions

1
vote
1answer
399 views

Create a function with Dt[x] as a variable

I have a function (for example F[x_]:=Cos[x]). I want to define a function like Fdot[x_,xdot_]:=Dt[F[x]] where xdot represents Dt[x]. For example, to define Fdot one might naivley try Fdot[x_,Dt[...
2
votes
1answer
235 views

I want to compute the derivative of Black and Scholes option

Good evening to everybody, my question is about computing the derivative of a Black and Scholes option and to draw it. My code is ...
1
vote
1answer
231 views

Scope of dummy variables used in defining a function

I define a function and then define another function, using the same name for the dummy variables as I used for the first function. Will Mathematica use the first definition in the second definition? ...
1
vote
1answer
369 views

VectorPlot3D of the Electric Field E as Determined from the Potential V

I am new to Mathematica and I am trying to create the electric field $F$ from the electric potential $V$ (using arbitrary distances) and then plot the subsequent vector graph to show that the electric ...
1
vote
2answers
200 views

How to deal with the condition that a function own many options?

Assming that I have a function myFunc which has some options. ...
1
vote
1answer
512 views

NDSolve memory usage [closed]

I am trying to solve numerically a system of linear ODEs with some quickly varying driving functions. The basic command is: ...
2
votes
1answer
153 views

Unprotect fails the first time, works on second pass [duplicate]

I am redefining some of the standard math functions. I know this is dangerous, so I am trying to be extra careful. (For instance, in the redefinitions, I make sure to only match a custom head) The ...
0
votes
1answer
240 views

How to map a function over a dimension in a matrix? [closed]

I have a function g[x,r] yielding a 3x1 vector, where x is a ...
0
votes
1answer
239 views

Get imaginary part of symbolic expression [duplicate]

I define ψ1 = Sqrt[Subscript[ρ, 1][t]] E^(I Subscript[θ, 1][t]); ψ2 = Sqrt[Subscript[ρ, 2][t]] E^(I Subscript[θ, 2][t]); and ...
5
votes
2answers
122 views

Custom opaque operator with custom axioms?

Is there any way to define a custom opaque operator/function in Mathematica that satisfies custom axioms, so that the Mathematica engine can perform simplifications using those axioms? For example, ...
1
vote
2answers
143 views

How to define a function whose argument is in the replace list?

As a simplified example: In[780]:= f[x_] := a /. {a -> x}; f[1] Out[781]= 1 This yields the correct result. But ...
2
votes
1answer
273 views

Syntax f[x_][y_]

Need to understand the principle of the distinction between f[x_,y_] and f[x_][y_] It seems also that z[x_, y_][a_, b_, c_][α_, β_] := a (x + y)^b + c/(α-β) ...
3
votes
0answers
244 views

Measuring Temp on a cubical using heat equation with Neumann and Dirichlet boundary conditions

I'm trying to solve 3D heat equation to understand how the temperature varies with time on cubical. i have mixed boundary conditions: Dirichlet on the bottom surface (constant Temp) Neumann on all the ...
2
votes
3answers
65 views

Performing iterated integrals

I would like to define a function $f_n(x)$ and plot it with Manipulate. The function is defined by $$ f_{n+1}(x)=\frac{1}{\int_0^1(f_n(x'))^2dx'}\left(\int_0^xf_n(x'...
0
votes
1answer
166 views

for loop and list

I'm new to Mathematica. I want to built a function like that; ...

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