## 530 Reputation

8 years, 138 days

## I agree...

According to your code, the solution  ( analytic) from 10 is close to the numeric solution.
I tested both with the solution obtained from finite difference ( Crank Nicholson finite difference).
But, at endpoints, there is small oscillation...I feel that there is someting wrong ( in my code) but all matrices are correct, rhs is correct, CG is corrected.

## @Carl Love  Thank you for this rem...

Thank you for this remark. I appreciate always your remarks.
If I change the time step and spacestep in my code, the solution behaviors change comppletely...moreover,

I tested both at t=0.49, there is a strange phenomena at the end of interval...
All matrices introduced are correct....
But, I cannt understand what happen...

New_code.mw

## x-axis bound problem...

When I plot using your line code, I get the x-axis from 1 to 11

But, U(x,t), is function with x from 0 to 1
How, can I get my original  x-axis limits

## @Kitonum  Thank you for your remar...

I applied the CGM to a sparse , symmetric matrix but I get divergence when I solve a linear system

## @dharr  Thank you for your remark&...

I applied the same method to solve  A U[n+1]=B U[n]+M, at each iteration, but there is divergence of the methdod

problem_convergence.mw

I get divergence

I hope find an answer thank you

## two different curve...

Thak you I agree with you.
But, f(x) and Natural spline are two different functions, I must have two different curve, why in plot give me only one curve

## @Carl Love  Thank you, now its wor...

Thank you, now its working.
How can  I use series in Unapply, so that I can display all peicewise functions. If I have two or three for four I can modify by hand but If I have more how can I use many peices in piecewise with unapply

splineProb.mw

Thank you

## @Scot Gould  I would like to print...

I would like to print the entries of G, by using print(G) nothing printed.

I think,  nn is not updated in the loop

## I tried  copy or format to copy th...

I tried

copy or format to copy the entries I get a bad shape of table ( copy and paste in powerpoint )

Maybe can i take the table from maple as figure, so that I can insert the figure in powepoint

## Error, (in Matrix) this entry is too tal...

@Carl Love
Thank you very much for your remarks, I appreciate all  remarks proposed, your remarks added in the code , but I get
Error, (in Matrix) this entry is too tall or too short: tab_err

integ_R.mw

thank you

## @dharr  I moved that part to displ...

I moved that part to display tab_err before return, but unfortunattely no  tabl_err displayed  and the command plot does not working ( no figure obtained)

integ_R.mw

## problem solved...

trap.mw

Now, it okay, there is no problem I get the same result.