@dharr is more than two month I am busy with this I have a question why they are talk about bilinear form? in this equation you did it without bilinear form, also for finding R again you did something new always I do iteration for finding R I have one paper just one exist which did it like series iteration I don't know how work with it I will post that too but now I must find each structure, I will solve more of equations like you did and I will try work on bilinear form too, this work you did made my day thank you so much 

@janhardo ...

@dharr i am so sorry but i try 

s2.mw

@dharr  i can't find it the code you did it before for me but i don't remember where i save it

@dharr  something strange happen in here you are right it is run and simplify, but when i  want find parameter i have squar root i must give them a constant name in algsub or what really i need help ?

s2.mw

@dharr thank you so much dear Dr. i owe you so much, now is my turn to looking for solution of each one , i am just so happy with this really is unblevieble 

@dharr  you are emazing dear Dr

@dharr  you are right is not clear so much i have a lot of example i will put here more, and in fact i am stuck is this kind of solution there is some people very well do this definition and really i want to do too, if i apply this i can solve a lot of equation of PDE , if i found the f[N] in any N i can find N soliton , sorry for late i have them in hard copy i downlaod them again ... i hope help me for finding this is so important for me

@dharr  so i watch the different between mine and yours is just there in this line i didn't put : ->eq6 := eval(L4, {t^2 = Z, x^2 = X, y^2 = Y}) is this different so if i put this in last of each equation is remove the issue ?

@dharr it is work thank you dear Dr

@mmcdara so good but is so high level 

@acer  it help me a lot is big help thank you so much 

@acer  the plot of the countor is same is like yours but density is different  i don't know How he get the density the countor in matlab is not like that is so different but  i need all of thus plots i don't know why density is so different from this

this picture is another function in that paper 

@acer  i forget to add this picture , this is middle one is density also i want countor plot i don't have the code for countor plot in maple

@dharr I didn't delete thus post moderator did,thank you so much