Complex integral using matlab

up vote
0
down vote

favorite

Let $f(s)$ be a function. I would like to compute the following integral using Matlab

$$
I=int_{c-iinfty}^{c+iinfty}f(s)s^{-s}ds.
$$

How can we use Matlab to evaluate this integral.
Is the following notation convenient :

syms s x

int(f,x,c-iinfty+c,c+iinfty) ?

Thanks

edited Nov 16 at 11:01

Jean Marie

28.1k41848

asked Sep 30 at 15:39

Monir

116

add a comment |

up vote
0
down vote

favorite

Let $f(s)$ be a function. I would like to compute the following integral using Matlab

$$
I=int_{c-iinfty}^{c+iinfty}f(s)s^{-s}ds.
$$

How can we use Matlab to evaluate this integral.
Is the following notation convenient :

syms s x

int(f,x,c-iinfty+c,c+iinfty) ?

Thanks

edited Nov 16 at 11:01

Jean Marie

28.1k41848

asked Sep 30 at 15:39

Monir

116

add a comment |

up vote
0
down vote

favorite

Let $f(s)$ be a function. I would like to compute the following integral using Matlab

$$
I=int_{c-iinfty}^{c+iinfty}f(s)s^{-s}ds.
$$

How can we use Matlab to evaluate this integral.
Is the following notation convenient :

syms s x

int(f,x,c-iinfty+c,c+iinfty) ?

Thanks

edited Nov 16 at 11:01

Jean Marie

28.1k41848

asked Sep 30 at 15:39

Monir

116

Let $f(s)$ be a function. I would like to compute the following integral using Matlab

$$
I=int_{c-iinfty}^{c+iinfty}f(s)s^{-s}ds.
$$

How can we use Matlab to evaluate this integral.
Is the following notation convenient :

syms s x

int(f,x,c-iinfty+c,c+iinfty) ?

Thanks

matlab

edited Nov 16 at 11:01

Jean Marie

28.1k41848

asked Sep 30 at 15:39

Monir

116

edited Nov 16 at 11:01

Jean Marie

28.1k41848

asked Sep 30 at 15:39

Monir

116

edited Nov 16 at 11:01

Jean Marie

28.1k41848

edited Nov 16 at 11:01

Jean Marie

28.1k41848

edited Nov 16 at 11:01

Jean Marie

28.1k41848

asked Sep 30 at 15:39

Monir

116

asked Sep 30 at 15:39

Monir

116

asked Sep 30 at 15:39

Monir

116

add a comment |

1 Answer
1

active

oldest

votes

up vote
0
down vote

You aren't allowed to use $infty$ (which is "inf" with Matlab) in such a case.

You have to replace it by a large enough number.

Here is the right way to do it, through an example (which is in fact classical)

clear all;close all;format long

a=rand;

f=@(z)(exp(z.^2));

I=integral(f,a-i*1000,a+i*1000)

J=i*sqrt(pi)

% theoretical result : I = J whatever the value of a

% practical result : I and J coincide up to the 15th decimal place !

edited Nov 16 at 23:11

answered Nov 16 at 11:22

Jean Marie

28.1k41848

add a comment |

Your Answer

StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\$","\$"]]);
});
});
}, "mathjax-editing");

StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "69"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});

function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});

}
});

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f2936804%2fcomplex-integral-using-matlab%23new-answer', 'question_page');
}
);

Post as a guest

Name

Required, but never shown

1 Answer
1

active

oldest

votes

1 Answer
1

active

oldest

votes

up vote
0
down vote

You aren't allowed to use $infty$ (which is "inf" with Matlab) in such a case.

You have to replace it by a large enough number.

Here is the right way to do it, through an example (which is in fact classical)

clear all;close all;format long

a=rand;

f=@(z)(exp(z.^2));

I=integral(f,a-i*1000,a+i*1000)

J=i*sqrt(pi)

% theoretical result : I = J whatever the value of a

% practical result : I and J coincide up to the 15th decimal place !

edited Nov 16 at 23:11

answered Nov 16 at 11:22

Jean Marie

28.1k41848

add a comment |

up vote
0
down vote

You aren't allowed to use $infty$ (which is "inf" with Matlab) in such a case.

You have to replace it by a large enough number.

Here is the right way to do it, through an example (which is in fact classical)

clear all;close all;format long

a=rand;

f=@(z)(exp(z.^2));

I=integral(f,a-i*1000,a+i*1000)

J=i*sqrt(pi)

% theoretical result : I = J whatever the value of a

% practical result : I and J coincide up to the 15th decimal place !

edited Nov 16 at 23:11

answered Nov 16 at 11:22

Jean Marie

28.1k41848

add a comment |

up vote
0
down vote

You aren't allowed to use $infty$ (which is "inf" with Matlab) in such a case.

You have to replace it by a large enough number.

Here is the right way to do it, through an example (which is in fact classical)

clear all;close all;format long

a=rand;

f=@(z)(exp(z.^2));

I=integral(f,a-i*1000,a+i*1000)

J=i*sqrt(pi)

% theoretical result : I = J whatever the value of a

% practical result : I and J coincide up to the 15th decimal place !

edited Nov 16 at 23:11

answered Nov 16 at 11:22

Jean Marie

28.1k41848

You aren't allowed to use $infty$ (which is "inf" with Matlab) in such a case.

You have to replace it by a large enough number.

Here is the right way to do it, through an example (which is in fact classical)

clear all;close all;format long

a=rand;

f=@(z)(exp(z.^2));

I=integral(f,a-i*1000,a+i*1000)

J=i*sqrt(pi)

% theoretical result : I = J whatever the value of a

% practical result : I and J coincide up to the 15th decimal place !

edited Nov 16 at 23:11

answered Nov 16 at 11:22

Jean Marie

28.1k41848

edited Nov 16 at 23:11

answered Nov 16 at 11:22

Jean Marie

28.1k41848

answered Nov 16 at 11:22

Jean Marie

28.1k41848

answered Nov 16 at 11:22

Jean Marie

28.1k41848

add a comment |

draft saved

draft discarded

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Post as a guest

Name

Required, but never shown

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Name

Required, but never shown

Name

Required, but never shown

This page is only for reference, If you need detailed information, please check here

搜尋此網誌

Krdytkyu