Thank you Preben!

Thank you so much. Since I prefer function because of easier plotting function, So the function method is more useful for me. Thanks again.

Thank you so much. Since I prefer function because of easier plotting function, So the function method is more useful for me. Thanks again.

Dear friends specially Alec and Dr./Prof. Meade, Thank you for your helpful responses. I think for my problem at hand I should use the animate function, however I think it is useful if arbitrary increment is added in maple and compiled as is done in MATLAB for example. Sometimes it can really help. Regards, Hamidreza,

Thank you for the response. But my main problem arises when I want to plot some functions which are put in a sequence by the command below. print(display(seq(plot(myFunctionList[plotCounter], `&theta` = 0 .. 2*Pi, title = plotTitle), plotCounter = 1 .. nops(drivingForceList)), insequence = true)); Sometimes my program obtains more than e.g. 200 functions and I would like to see their behaviors at each 5 steps for example, because surprisingly this command fails to generate a "gif" file when the number of the functions increases that much. Therefore I want to reduce the number of the functions by dropping some of them in between sequentially. P.S. myFunctionList[plotCounter] returns a function of my variable, `&theta`.

Thank you for the response. But my main problem arises when I want to plot some functions which are put in a sequence by the command below. print(display(seq(plot(myFunctionList[plotCounter], `&theta` = 0 .. 2*Pi, title = plotTitle), plotCounter = 1 .. nops(drivingForceList)), insequence = true)); Sometimes my program obtains more than e.g. 200 functions and I would like to see their behaviors at each 5 steps for example, because surprisingly this command fails to generate a "gif" file when the number of the functions increases that much. Therefore I want to reduce the number of the functions by dropping some of them in between sequentially. P.S. myFunctionList[plotCounter] returns a function of my variable, `&theta`.

Thank you! Maximize is also a faster way.

Thank you! Maximize is also a faster way.

Dear Dr. Israel, Thank you for the informatively useful explanation. In fact, for my numerical problem if my function satisfies positiveness for even some incremental values of its range, it is fine with me; as I am plotting the trend of each function to see if somewhere it goes negative or not. If the 'verify', as a built-in function, can be someway customized such that I can check the positiveness of my function within that range and with my defined specified values of `θ_e`, that would also be good. When I checked the features of 'assume' function I could not find a way to define it as I explained. Regards, Hamidreza,

Dear Dr. Israel, Thank you for the informatively useful explanation. In fact, for my numerical problem if my function satisfies positiveness for even some incremental values of its range, it is fine with me; as I am plotting the trend of each function to see if somewhere it goes negative or not. If the 'verify', as a built-in function, can be someway customized such that I can check the positiveness of my function within that range and with my defined specified values of `θ_e`, that would also be good. When I checked the features of 'assume' function I could not find a way to define it as I explained. Regards, Hamidreza,

Hi Eric, Thank you for the reply. `θ_e` is just a variable name like `θ`, because I am using `θ` somewhere else in the code and I had to introduce a new variable for the new function. Anyway, sorry for the confusion. 'drivingForce' is a complicated function of `θ_e`and I am calculating this function in each loop iteration. For example, if I have 100 iteration, I will obtain 100 drivingForce corresponding to each iteration number, then I am going plot them individually. From these functions, I am interested in those which are positive when 0<`θ_e`<2 pi; and that's why I am using the verify function. Now one strange thing is what I explained before (not responding for a long time), and the 2nd strange thing is that when I tried to apply verify function on its simplified form ( i.e. verify(simplify(drivingForce)) ) the results are different!!! I am confused whether something is wrong with simplify too?

Hi Eric, Thank you for the reply. `θ_e` is just a variable name like `θ`, because I am using `θ` somewhere else in the code and I had to introduce a new variable for the new function. Anyway, sorry for the confusion. 'drivingForce' is a complicated function of `θ_e`and I am calculating this function in each loop iteration. For example, if I have 100 iteration, I will obtain 100 drivingForce corresponding to each iteration number, then I am going plot them individually. From these functions, I am interested in those which are positive when 0<`θ_e`<2 pi; and that's why I am using the verify function. Now one strange thing is what I explained before (not responding for a long time), and the 2nd strange thing is that when I tried to apply verify function on its simplified form ( i.e. verify(simplify(drivingForce)) ) the results are different!!! I am confused whether something is wrong with simplify too?

Excuse me algsubs! I think your message was not posted completely. Can you send it once again? thanx

Excuse me algsubs! I think your message was not posted completely. Can you send it once again? thanx

Thank you PatrickT, Since I am using Maple 13, normal copy-paste doesn't work as what you have written. FF3 is the answer of the DE, so it is unknown. In case FF4 is just a constant, it gives me the right answer, so I think that dsolve doesn't report even a warning when it can not solve a DE. Regards,