someone help me plzzz :(

tic
syms x y;
f(x) = (2.*x-1).*sin(pi.*x);
for i=1:25
    y(i)=diff(f(x),i);
end
fun=matlabFunction(y');
x=-2:0.01:1;
result=fun(x);
maxres = max(result,[],2)
for i=1:25
    if maxres(i)<0.001
        break
    end 
end

someone can tell me the way to find max y(i) = diff (f(x),i) in every step and check it

if max(y(i))< 0.001 then stop the loop

[madhan ravi]

isn't https://www.mathworks.com/matlabcentral/answers/437029-help-me-to-find-max the same question ?

Answer 1

[madhan ravi]

syms x y;
f(x) = (2.*x-1).*sin(pi.*x);
y=zeros(1,25);
for i=1:25
    y(i)=diff(f(x),i);
end
fun=matlabFunction(y.');
x=-2:0.01:1;
result=fun(x);
maxres = max(result,[],2)
maxres(abs(maxres-0.001)<1e-4)  % will return empty because none of the results satisfy the condition

[Phuc Nguyen Quy]

syms x y;
f(x) = (2.*x-1).*sin(pi.*x);
Pn30(x) = taylor(f,'order',30);
terms=children(Pn30);
y(1)=f(x)-terms(1);
for i=2:25
    y(i)=y(i-1)-terms(i);
end
fun=matlabFunction(abs(y)');
x=-2:0.01:1;
result=fun(x);
maxres = max(result,[],2)
maxres(abs(maxres-0.001)<1e-4) % but now we have the results satisfy the condition but this return nothing

[madhan ravi]

what's your question ? simply posting the code is meaningless..

[Phuc Nguyen Quy]

in the loop with any i

i can find max y(i) then

compare if max(y(i))<0.001

break loop

[madhan ravi]

Alright try this:

syms x;
a = -2;
b = 1;
f(x) = (2.*x-1).*sin(pi.*x);
Pn10(x) = taylor(f,'order',30);
xMin = a; xMax = b; stepSize = 0.01;
terms = children(Pn10);
y(x) = terms;
x=-2:0.01:1;
Y = cellfun(@max,y(x)) ;
Final_result=[];
for i = 1:numel(Y)
    if abs(Y(i)-0.001)<1e-4
       break
    else 
        Final_result=vpa(Y(i));
    end
end

[Phuc Nguyen Quy]

but this one

solve every Y ( with cellfun)

do u know how to find max in every single step in loop

then i can check result (max<0.001)

[madhan ravi]

Final try rectified the mistakes you can also comapre the results with cellfun it will be the same:

syms x
f(x) = (2.*x-1).*sin(pi.*x);
Pn10(x) = taylor(f,'order',30);
terms = children(Pn10);
y(x) = terms;
x=-2:0.01:1;
Y = y(x);
a=[];
Result=[];
for i = 1:numel(Y)
    a(i) = max([Y{i}]);
    if a(i) < 0.001
        break
    else
        Result(i)=a(i);
    end
end

[Phuc Nguyen Quy]

i did it

thank u so much <3

[madhan ravi]

Anytime :)

Answer 2

[KSSV]

f= @(x) (2.*x-1).*sin(pi.*x);
x=-2:0.01:1;

for i=1:25
    y=diff(f(x),i);
    if max(y)<0.001
        break
    end
end