## 90 Reputation

14 years, 22 days

## find max of values, save solve values...

Maple

Hello

I am trying to find the maximum of values in dsolve. In part 1 we solve the equation. In part 2 we do a doolop to know the values for specific time such as t=2. In part 3 we try to give this values names such as y[i] then to find the maximum of these values but it did not work for the maximum it gave y6 instead of the value.

Also, is it possible to save all values from dsolve  to a file the call it to find the maximum at each t?

## shaded area in plot and 95% confidence i...

Maple

Hello,

I am trying to get a shaded area in my plot but I could not.

First we solve ODE without randomness:

ode := diff(U(t), t) = -(A+B*U(t))*U(t);

Then we add randomness to ODE and solve:

ode2 := diff(U(t), t) = -(A+r(t)+B*U(t))*U(t);

A with randomness for r in R=( - 0.0001/365, 0.0001/365) is:

A(t,r)= A+r

Where A is constant =  0.0001/365

We plot both solution. For the plot I...

## plot for different values (frame)...

Maple

Hello,

I am trying to plot the solution for eq1 and eq2 for different values of mu.  When I plot  this:

f := proc (x) options operator, arrow; mu*abs(F[N]-g)*signum(x(t)) end proc;

it works.

When I do the same for the solution it won’t work.

This is the code:

> restart;

> with(plots);

> with(DEtools);

> k := 100; L := .25; M := .5; g := 4; mu := 0.2e-1;

## E with one random variable...

Maple

Hello,

I am trying to add a random variable in ODE and solve it.

I chose A as the random variable.

Randomness in A will define like:

A with randomness for s in S=(-0.05,0.75) is:

A(t,s)= A`(t)+s

Where A`(t)= 0.25+ 0.0037t , if 0<= (t,365)<=182

0.5+ 0.0045 t  , if 182<= (t,365)<=365

## if statement: Error, cannot determine if...

Maple
`Hello,`
`I am trying to add an if statement to maple code for example if U(tk) less or equal to 4 then `
`the initial condition=0 else the initial condition=value .`
` `
`I am getting this error:`
`Error, cannot determine if this expression is true or false: U(365)`

`restart;`

k := 0; B[1] := 0.001/365; B[2] :=0.002/365:

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