Items tagged with function function Tagged Items Feed

Hi everyone,

I have a very complicated function y with only one independent variable x, and want to fit or approximate it by a simpler function, say polynomial. Many books or maple reference seem to tell how to fit a set of data instead of a given function. But the argument x in the function is assumed to be continuous other than discrete, so I don't know whether it is possible to express datax in form of x's range such as 0..1, and express datay in form of the function. After that , maybe I can fit the two created data sets by a polynomial function.

Or, does anyone have a better or more direct way to do the fitting linking two fucntions?

I am appreciated for your help.



hello. before I used Mapple 15. But then I`ve run Mapple 16 and now I`ve a problem. I can`t use this program. I open the program, everthing is in the rule, but if I want to write any mathemathical function, or a letter, such as- x or x+2, the program does`t give any reaction. program only gives reaction the numbers.

Please, help me. (my english isn`t very good, and I don`t know I`ve explained my opinion).

Hi all, 

I am quite new to maple. Thanks for your help in advance. 

Could I define a general function f of a single variable x, f(x), without specifying its explicit form? I know it is simple to define functions of specific forms, e.g., f(x)=2*x (In maple: f:=x->2*x). I try to define a function without knowing its form, e.g., f:=x->f(x), expecting maple return f(y) if I type >>f(y). But this does not work (Maple says:

Error, (in temp) too many levels of recursion). 


Is it possible to define a general function f(x) without specific form in maple? Thank you again. 

my question may be simple but I don't find the answer in any help guide.
when I define a function I cannot use a linearalgebra expression such as Trace.
Here is an example of what I would like to do:

If anyone can help me...
Thank you


First of all, I've searched already a bit around, but couldn't find a similar topic, so I thought I'd open a new one. Also, English isn't my main language, so terminology may be wrong, but I hope you'll still understand what I want to say.

So, I have this procedure:

functions:= proc(n)
local L, list, p, f, sum, i, part, g, normg, x:

for p from 2 to n do
f := x**(p-1):
sum := 0:

for i from 1 to (p-1) do
part:= int(list[i]*f*(x+1),x=-1..1)*list[i]:
sum := sum + part:
end do:

g:= f-sum:
normg:= sqrt(int(g^2*(x+1),x = -1..1)):
list := [op(list), unapply(L,x)]:
end do:
end proc:

What this procedure does, is calculating n orthonormal functions (but that doesn't really matter here). The result is a list of functions, or should be. What I get when I enter e.g. functions(5), is a list of very weird functions with 'nexpr' and more, instead of some polynomials.
When I replace the 'unapply(L,x)' in the 4th last line by just 'L', I do get the correct expressions, but I can't manage to calculate the function values for those. The expression just gets returned. By the way, I can't do that in the situation before the edit either.

So what I eventually want to do, is calculating some function values for each function in the list, or (if this isn't the right terminology) in Maple code e.g.:

f:= x -> x^2 + 3*x;
(The result should be 18 in this case)

Could someone help me? :)


sol := dsolve([ode2, theta(0) = (1/180)*Pi*10, (D(theta))(0) = 0], numeric)


[t = 0., theta(t) = .174532925199433, diff(theta(t), t) = 0.]

given a numerical solution in the above form, how can I integrate a function

f(theta(t)) numerically?

I tried to isolate theta(t) first:


But I can't integrate


Hi everyone, I'm trying to find the value of f but I always have this error message : Error, (in BesselJ) too many levels of recursion.

Here is the function:

f(t)=BesselJ(0, t)+int(BesselJ(0, x)*f(t-x), x = 0 .. t)


Is there any way that I can isolate my f without having to rewrite the equation using laplace transform properties?



I need help writing a function which takes a number of integers (which are greater than or equal to 2) and returns a list where the nth entry in the list is given by the number of arguments which can be expressed in the form of x^n where x is an integer. The function must also disregard all of the terms after the final integer greater than 0 is produced ie does not show 0, 0, 0, 0, at the end of the list.

Eg if f was the function f(27) = [1,0,1]

f(2,3,4,9,81,1024) = [6,4,0,1,1,0,0,0,0,1]

I define a func

f(x,y):=piecewise(x=0 and y=0,139 ,x=1 and y=0,144,x=2 and y=0,149,x=3 and y=0,155,x=4 and y=0,155,x=5 and y=0,155,x=6 and y=0,155,x=7 and y=0,155,x=0 and y=1,144,x=1 and y=1,151,x=2 and y=1,153,x=3 and y=1,156,x=4 and y=1,159,x=5 and y=1,159,x=6 and y=1,159,x=7 and y=1,159,x=0 and y=2,150,x=1 and y=2,155,x=2 and y=2,160,x=3 and y=2,163,x=4 and y=2,158,x=5 and y=2,156,x=6 and y=2,156,x=7 and y=2,156,x=0 and y=3,159,x=1 and y=3,161,x=2 and y=3,162,x=3 and y=3,160,x=4 and y=3,160,x=5 and y=3,159,x=6 and y=3,159,x=7 and y=3,159,x=0 and y=4,159,x=1 and y=4,160,x=2 and y=4,161,x=3 and y=4,162,x=4 and y=4,162,x=5 and y=4,155,x=6 and y=4,155,x=7 and y=4,155,x=0 and y=5,161,x=1 and y=5,161,x=2 and y=5,161,x=3 and y=5,161,x=4 and y=5,160,x=5 and y=5,157,x=6 and y=5,157,x=7 and y=5,157,x=0 and y=6,162,x=1 and y=6,162,x=2 and y=6,161,x=3 and y=6,163,x=4 and y=6,162,x=5 and y=6,157,x=6 and y=6,157,x=7 and y=6,157,x=0 and y=7,162,x=1 and y=7,162,x=2 and y=7,161,x=3 and y=7,161,x=4 and y=7,163,x=5 and y=7,158,x=6 and y=7,158,x=7 and y=7,158)

It is really a chore . By the way , is there more concise way to definition of the same effet as this ? 

then I type:

sum(f(0, y), y = 0 .. 7) 

Maple just respond me a 0 

why ?

I need to create a function from one list to another, but I don't want to define an operation.  I only want to assign a 1-1 mapping from a list of 64 elements to another list of 64 elements, i.e. the 1st element in list a is assigned to the 1st element in list b, etc.  I see plenty of examples of how to do this with an operation, but I don't want the mapping to perform any operation, just the mapping.  How is this done?

Please have a visit of this qestion ``. I did a very elementary attempt there for example for a function:

 > with(plots):
      h := x->piecewise(x < -2, x+3, x <= 2, 5-x^2, 3-x):
      a:= plot(h(x), x = 0 .. 10, color = red, thickness = 3):
      b:= plot(t(x), x = -10 .. 0, color = green, thickness = 3):

But  I am eager to know  the formal codes if they exists. Thanks for your time.

I can't seem to find what's wrong with this function:

F:= x-> (-c-ax)/b;
G:=x-> (-d-ex)/f;
If -a/b = -e/f then print (false) else print (true); end if;


For a control systems project I'am working on I need to minimize the actuator effort required to control an input voltage to certain output voltage. As a first experiment I chose a sinusoidal input ug and a sinusoidal output ul. The function to minimize is the funtion Uint. We know that when both the input voltage and output voltage share the frequency, phase and amplitude, that the control effort is zero. Running the animation (see Maple input below) shows that if the input and output voltage frequencies approach eachother the function Uint goes to zero. However, if the frequencies exactly match and I evaluate the function Uint I get a devision by zero notification (this could already be seen from the function of Uint). How can I solve this?



u[G] := sin(omega[G]*t)

u[L] := sin(omega[L]*t)

U[int] := int((u[G]-u[L])^2, t)

omega[G] := 9:

animate(plot, [[u[G], u[L], (1/10)*U[int]], t = 0 .. 5, legend = ["Public grid voltage", "Local grid voltage (control goal)", "Cum. Actuator voltage (scaled)"]], omega[L] = 8 .. 10, gridlines = true, labels = ["Time [s]","Voltage [V]"], labeldirections = ["horizontal", "vertical"], labelfont = ["ARIAL", "bold", 12])

omega[L] := 9; t := 10; evalf(U[int])






Is there any way to write a function that determines the area of any n-sided polygon determined by a sequence of points? ie [[x_1, y_1]. [x_2, y_2], ... [x_n, y_n]] while returning 0 if any of the 2 segments intersect, otherwise print the area. Thanks for any help

I've been on this question a week now and still no conclusive answer! What I need is a function that produces the inequalities that determine a triangle given the 3 points and then using a 4th point, prints true if the 4th point satisfies 2 or 3 or the inequalities and prints false if it only satisfies 1 or none of the inequalities. I need to have this solved by tonight so any quick help would be greatly appreciated!

5 6 7 8 9 10 11 Last Page 7 of 23