Definition of Probability mass function of a random process.











up vote
0
down vote

favorite












A random process $X(t)$ is defined as $X(t)=1, 0leq t leq Y$ and $0$ otherwise where $Y$ follows an exponential distribution. What is the $pmf$ of $X(t)$



I am a bit confused on the definition of $pmf$ for random process. By definition, the pmf of $X(t)$ is
$$Pr({ X(t, xi)=1 })=Pr({ (t, xi) | 0leq t leq xi })=int_0^{infty}int_0^xi f(t,xi)dtdxi$$



However, I am confused how I can calculate $f(t, xi)$. I know from the question that $f(xi) = lambda e^{-lambda xi}$ where $lambda$ is the parameter of the geometric distribution. But I don't see how to get $f(t,xi)$










share|cite|improve this question
























  • My guess is that the question asks you to find the distribution of $X(t)$ for a fixed $t$ (and this is trivial). The distribution of the entire process is a measure on an infinite dimensional function space.
    – Kavi Rama Murthy
    Nov 27 at 9:13










  • @KaviRamaMurthy That makes a lot more sense now. Just integrate from $t$ to infinity the geometric pdf. This is one of the reason I don't like the notation of suppressing the sample space in random processes. It just makes things more confusing for learners such as myself. Thank you!
    – AspiringMat
    Nov 27 at 9:22















up vote
0
down vote

favorite












A random process $X(t)$ is defined as $X(t)=1, 0leq t leq Y$ and $0$ otherwise where $Y$ follows an exponential distribution. What is the $pmf$ of $X(t)$



I am a bit confused on the definition of $pmf$ for random process. By definition, the pmf of $X(t)$ is
$$Pr({ X(t, xi)=1 })=Pr({ (t, xi) | 0leq t leq xi })=int_0^{infty}int_0^xi f(t,xi)dtdxi$$



However, I am confused how I can calculate $f(t, xi)$. I know from the question that $f(xi) = lambda e^{-lambda xi}$ where $lambda$ is the parameter of the geometric distribution. But I don't see how to get $f(t,xi)$










share|cite|improve this question
























  • My guess is that the question asks you to find the distribution of $X(t)$ for a fixed $t$ (and this is trivial). The distribution of the entire process is a measure on an infinite dimensional function space.
    – Kavi Rama Murthy
    Nov 27 at 9:13










  • @KaviRamaMurthy That makes a lot more sense now. Just integrate from $t$ to infinity the geometric pdf. This is one of the reason I don't like the notation of suppressing the sample space in random processes. It just makes things more confusing for learners such as myself. Thank you!
    – AspiringMat
    Nov 27 at 9:22













up vote
0
down vote

favorite









up vote
0
down vote

favorite











A random process $X(t)$ is defined as $X(t)=1, 0leq t leq Y$ and $0$ otherwise where $Y$ follows an exponential distribution. What is the $pmf$ of $X(t)$



I am a bit confused on the definition of $pmf$ for random process. By definition, the pmf of $X(t)$ is
$$Pr({ X(t, xi)=1 })=Pr({ (t, xi) | 0leq t leq xi })=int_0^{infty}int_0^xi f(t,xi)dtdxi$$



However, I am confused how I can calculate $f(t, xi)$. I know from the question that $f(xi) = lambda e^{-lambda xi}$ where $lambda$ is the parameter of the geometric distribution. But I don't see how to get $f(t,xi)$










share|cite|improve this question















A random process $X(t)$ is defined as $X(t)=1, 0leq t leq Y$ and $0$ otherwise where $Y$ follows an exponential distribution. What is the $pmf$ of $X(t)$



I am a bit confused on the definition of $pmf$ for random process. By definition, the pmf of $X(t)$ is
$$Pr({ X(t, xi)=1 })=Pr({ (t, xi) | 0leq t leq xi })=int_0^{infty}int_0^xi f(t,xi)dtdxi$$



However, I am confused how I can calculate $f(t, xi)$. I know from the question that $f(xi) = lambda e^{-lambda xi}$ where $lambda$ is the parameter of the geometric distribution. But I don't see how to get $f(t,xi)$







stochastic-processes






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Nov 27 at 9:09

























asked Nov 27 at 8:58









AspiringMat

535518




535518












  • My guess is that the question asks you to find the distribution of $X(t)$ for a fixed $t$ (and this is trivial). The distribution of the entire process is a measure on an infinite dimensional function space.
    – Kavi Rama Murthy
    Nov 27 at 9:13










  • @KaviRamaMurthy That makes a lot more sense now. Just integrate from $t$ to infinity the geometric pdf. This is one of the reason I don't like the notation of suppressing the sample space in random processes. It just makes things more confusing for learners such as myself. Thank you!
    – AspiringMat
    Nov 27 at 9:22


















  • My guess is that the question asks you to find the distribution of $X(t)$ for a fixed $t$ (and this is trivial). The distribution of the entire process is a measure on an infinite dimensional function space.
    – Kavi Rama Murthy
    Nov 27 at 9:13










  • @KaviRamaMurthy That makes a lot more sense now. Just integrate from $t$ to infinity the geometric pdf. This is one of the reason I don't like the notation of suppressing the sample space in random processes. It just makes things more confusing for learners such as myself. Thank you!
    – AspiringMat
    Nov 27 at 9:22
















My guess is that the question asks you to find the distribution of $X(t)$ for a fixed $t$ (and this is trivial). The distribution of the entire process is a measure on an infinite dimensional function space.
– Kavi Rama Murthy
Nov 27 at 9:13




My guess is that the question asks you to find the distribution of $X(t)$ for a fixed $t$ (and this is trivial). The distribution of the entire process is a measure on an infinite dimensional function space.
– Kavi Rama Murthy
Nov 27 at 9:13












@KaviRamaMurthy That makes a lot more sense now. Just integrate from $t$ to infinity the geometric pdf. This is one of the reason I don't like the notation of suppressing the sample space in random processes. It just makes things more confusing for learners such as myself. Thank you!
– AspiringMat
Nov 27 at 9:22




@KaviRamaMurthy That makes a lot more sense now. Just integrate from $t$ to infinity the geometric pdf. This is one of the reason I don't like the notation of suppressing the sample space in random processes. It just makes things more confusing for learners such as myself. Thank you!
– AspiringMat
Nov 27 at 9:22















active

oldest

votes











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


















StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3015526%2fdefinition-of-probability-mass-function-of-a-random-process%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown






























active

oldest

votes













active

oldest

votes









active

oldest

votes






active

oldest

votes
















draft saved

draft discarded




















































Thanks for contributing an answer to Mathematics Stack Exchange!


  • Please be sure to answer the question. Provide details and share your research!

But avoid



  • Asking for help, clarification, or responding to other answers.

  • Making statements based on opinion; back them up with references or personal experience.


Use MathJax to format equations. MathJax reference.


To learn more, see our tips on writing great answers.





Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


Please pay close attention to the following guidance:


  • Please be sure to answer the question. Provide details and share your research!

But avoid



  • Asking for help, clarification, or responding to other answers.

  • Making statements based on opinion; back them up with references or personal experience.


To learn more, see our tips on writing great answers.




draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3015526%2fdefinition-of-probability-mass-function-of-a-random-process%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown





















































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown

































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown







Popular posts from this blog

Wiesbaden

Marschland

Dieringhausen