The way to make an array using function_h​undle(関数ハン​ドルを用いた配列の作​り方)

関数ハンドルを用いた配列の作り方をご教授願いたいです。

例えば、

for i=1:5, f[i]=i.*x

としたときに

f[1]=x, f[2]=2.*x, f[3]=3.*x, f[4]=4.*x, f[5]=5.*x

といったデータが格納されるようなプログラムは可能しょうか？

ぜひよろしくお願いします。

I want the way to make an array using function_hundle.

For example, when I define

for i=1:5, f[i]=i.*x,

I wish to be stored

f[1]=x, f[2]=2.*x, f[3]=3.*x, f[4]=4.*x, f[5]=5.*x.

Please tell me the way...

Thank you.

[sushanth govinahallisathyanarayana]

Is x an array or a single number?

vec=1:5

if it is a single number, then

f=vec.*x

if x is an array, then

f=x(:)*vec.' (assuming vec is a column vector)

Each column of vec will be x multiplied by the corresponding number.

Hope this helps.

[Yoshiki Sato]

Thank you for your support.

x is a variable.

So, I want to get 5 function_fundles.

Could you give me any ideas?

I'm sorry for that I'm poor in English and Matlab...

Thank you.

Answer 1

[Walter Roberson]

N = 5;
f = cell(N,1);
for i = 1 : N
    f{i} = @(x) i.*x;
end

You cannot use () indexing to store different function handles; you have to use {} indexing.

[Yoshiki Sato]

>> N = 5;
f = cell(N,1);
for i = 1 : N
    f{i} = @(x) i.*x;
end
>> 
>> f{1}
ans =
  値をもつ function_handle:
    @(x)i.*x
>> f{2}
ans =
  値をもつ function_handle:
  @(x)i.*x

Thank you for your support.

On your way, I think all f{i} stores same function_hundle(@(x)i.*x).

I wish f{1} stores @(x)1.*x, f{2} stores @(x)2.*x...

Could you give me any ideas?

I'm sorry for that I'm poor in English and Matlab...

Thank you.

[Walter Roberson]

Try using them. They are not the same.

[Yoshiki Sato]

That was solved. Thank you so much!!

Answer 2

[KALYAN ACHARJYA]

Option 1:

i=1:5;
x=2;
f=i*x

Here resultant f array itself represents the f(1), f(2)..respectively depends on array length of i. Considering x is scalar.

Result:

f =
     2     4     6     8    10

Option 2:

Please note function handle is different

i=1:5;
fun=@(x) i*x;
fun(2)

here created function handle with x as inputs. Once you pass the input as defined, it gives the resultant value

fun(2)
%...^ x value 

You can create the function handle with both as inputs also

fun=@(i,x) i*x;

Result:

ans =
     2     4     6     8    10

Option 3:

Create MATLAB custom function, save in the same working directory as fun1.m

function f=fun1(i,x)
f=i*x;
end 

Now pass the input arguments from another matlab scripts or from command window

f=fun1(1:5,2)

Result:

>> f=fun1(1:5,2)
f =
     2     4     6     8    10

Hope it helps! Keep Learning!

[Yoshiki Sato]

Thank you for your support.

I wish to get 5 function_fundles like a Mr. Walter's way...

Could you give me any ideas?

I'm sorry for that I'm poor in English and Matlab...

Thank you.