What functions can be used to dilate a probability distribution function?












0












$begingroup$


Convolving any distribution $p(x)$ by a $delta(t-tau)$ will horizontally shift the distribution by $tau$. What mathematical operation can I perform on $p(x)$ that will horizontally dilate it (i.e., I want to generate some function $g(x)$ where $g(3x)=p(x)$). In my specific case, I'm working with probability distribution functions that I want to horizontally dilate by some constant.



New here, so please let me know if I should've asked the above question in a different way! Thanks!



Edit:
I mean probability density. To be more clear, I'm looking for a function that can be applied to p(x) directly instead of through substitution (i.e., $p(x) ?h(x)=g(x))$, where ? is some operator and $h(x)$ is some function/distribution. In the shifting example above, the delta function would be h(x).










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$endgroup$








  • 1




    $begingroup$
    Is $p(x)$ a probability density or a cumulative distribution function?
    $endgroup$
    – parsiad
    Dec 18 '18 at 2:24
















0












$begingroup$


Convolving any distribution $p(x)$ by a $delta(t-tau)$ will horizontally shift the distribution by $tau$. What mathematical operation can I perform on $p(x)$ that will horizontally dilate it (i.e., I want to generate some function $g(x)$ where $g(3x)=p(x)$). In my specific case, I'm working with probability distribution functions that I want to horizontally dilate by some constant.



New here, so please let me know if I should've asked the above question in a different way! Thanks!



Edit:
I mean probability density. To be more clear, I'm looking for a function that can be applied to p(x) directly instead of through substitution (i.e., $p(x) ?h(x)=g(x))$, where ? is some operator and $h(x)$ is some function/distribution. In the shifting example above, the delta function would be h(x).










share|cite|improve this question











$endgroup$








  • 1




    $begingroup$
    Is $p(x)$ a probability density or a cumulative distribution function?
    $endgroup$
    – parsiad
    Dec 18 '18 at 2:24














0












0








0





$begingroup$


Convolving any distribution $p(x)$ by a $delta(t-tau)$ will horizontally shift the distribution by $tau$. What mathematical operation can I perform on $p(x)$ that will horizontally dilate it (i.e., I want to generate some function $g(x)$ where $g(3x)=p(x)$). In my specific case, I'm working with probability distribution functions that I want to horizontally dilate by some constant.



New here, so please let me know if I should've asked the above question in a different way! Thanks!



Edit:
I mean probability density. To be more clear, I'm looking for a function that can be applied to p(x) directly instead of through substitution (i.e., $p(x) ?h(x)=g(x))$, where ? is some operator and $h(x)$ is some function/distribution. In the shifting example above, the delta function would be h(x).










share|cite|improve this question











$endgroup$




Convolving any distribution $p(x)$ by a $delta(t-tau)$ will horizontally shift the distribution by $tau$. What mathematical operation can I perform on $p(x)$ that will horizontally dilate it (i.e., I want to generate some function $g(x)$ where $g(3x)=p(x)$). In my specific case, I'm working with probability distribution functions that I want to horizontally dilate by some constant.



New here, so please let me know if I should've asked the above question in a different way! Thanks!



Edit:
I mean probability density. To be more clear, I'm looking for a function that can be applied to p(x) directly instead of through substitution (i.e., $p(x) ?h(x)=g(x))$, where ? is some operator and $h(x)$ is some function/distribution. In the shifting example above, the delta function would be h(x).







geometry statistics functions






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edited Dec 18 '18 at 4:31







regeneration

















asked Dec 18 '18 at 2:19









regenerationregeneration

11




11








  • 1




    $begingroup$
    Is $p(x)$ a probability density or a cumulative distribution function?
    $endgroup$
    – parsiad
    Dec 18 '18 at 2:24














  • 1




    $begingroup$
    Is $p(x)$ a probability density or a cumulative distribution function?
    $endgroup$
    – parsiad
    Dec 18 '18 at 2:24








1




1




$begingroup$
Is $p(x)$ a probability density or a cumulative distribution function?
$endgroup$
– parsiad
Dec 18 '18 at 2:24




$begingroup$
Is $p(x)$ a probability density or a cumulative distribution function?
$endgroup$
– parsiad
Dec 18 '18 at 2:24










1 Answer
1






active

oldest

votes


















0












$begingroup$

I'm assuming you meant probability density.



You know that
$$
int_{-infty}^{infty}p(x)dx=1.
$$

Using the substitution rule with $x=3y$,
$$
int_{-infty}^{infty}3p(3y)dy=1.
$$

So your "dilated" probability density is $ymapsto3p(3y)$.






share|cite|improve this answer









$endgroup$













  • $begingroup$
    Yes, I mean probability density. To be more clear, I'm looking for a function that can be applied to p(x) directly instead of through substitution (i.e., $p(x) ?h(x)=g(x))$, where ? is some operator and $h(x)$ is some function/distribution. In the shifting example above, the delta function would be h(x).
    $endgroup$
    – regeneration
    Dec 18 '18 at 4:31










  • $begingroup$
    Technically, $G$ defined by $(Gp)(y) = 3p(3y)$ is an operator... ;-)
    $endgroup$
    – parsiad
    Dec 18 '18 at 4:33












  • $begingroup$
    You should narrow down your problem though, as it stands, it's too broad. Maybe pick a specific operator (e.g., multiplication).
    $endgroup$
    – parsiad
    Dec 18 '18 at 4:35












  • $begingroup$
    Hmm I see. I've been thinking about mostly convolution or multiplication. In your example above you still don't derive an h(x) for $p(x)?h(x)=g(x)$. I'd like a form where I have both an operator (multiplication or convolution, ideally) and a function that does the transformation h(x).
    $endgroup$
    – regeneration
    Dec 18 '18 at 16:35











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1 Answer
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active

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1 Answer
1






active

oldest

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active

oldest

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active

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votes









0












$begingroup$

I'm assuming you meant probability density.



You know that
$$
int_{-infty}^{infty}p(x)dx=1.
$$

Using the substitution rule with $x=3y$,
$$
int_{-infty}^{infty}3p(3y)dy=1.
$$

So your "dilated" probability density is $ymapsto3p(3y)$.






share|cite|improve this answer









$endgroup$













  • $begingroup$
    Yes, I mean probability density. To be more clear, I'm looking for a function that can be applied to p(x) directly instead of through substitution (i.e., $p(x) ?h(x)=g(x))$, where ? is some operator and $h(x)$ is some function/distribution. In the shifting example above, the delta function would be h(x).
    $endgroup$
    – regeneration
    Dec 18 '18 at 4:31










  • $begingroup$
    Technically, $G$ defined by $(Gp)(y) = 3p(3y)$ is an operator... ;-)
    $endgroup$
    – parsiad
    Dec 18 '18 at 4:33












  • $begingroup$
    You should narrow down your problem though, as it stands, it's too broad. Maybe pick a specific operator (e.g., multiplication).
    $endgroup$
    – parsiad
    Dec 18 '18 at 4:35












  • $begingroup$
    Hmm I see. I've been thinking about mostly convolution or multiplication. In your example above you still don't derive an h(x) for $p(x)?h(x)=g(x)$. I'd like a form where I have both an operator (multiplication or convolution, ideally) and a function that does the transformation h(x).
    $endgroup$
    – regeneration
    Dec 18 '18 at 16:35
















0












$begingroup$

I'm assuming you meant probability density.



You know that
$$
int_{-infty}^{infty}p(x)dx=1.
$$

Using the substitution rule with $x=3y$,
$$
int_{-infty}^{infty}3p(3y)dy=1.
$$

So your "dilated" probability density is $ymapsto3p(3y)$.






share|cite|improve this answer









$endgroup$













  • $begingroup$
    Yes, I mean probability density. To be more clear, I'm looking for a function that can be applied to p(x) directly instead of through substitution (i.e., $p(x) ?h(x)=g(x))$, where ? is some operator and $h(x)$ is some function/distribution. In the shifting example above, the delta function would be h(x).
    $endgroup$
    – regeneration
    Dec 18 '18 at 4:31










  • $begingroup$
    Technically, $G$ defined by $(Gp)(y) = 3p(3y)$ is an operator... ;-)
    $endgroup$
    – parsiad
    Dec 18 '18 at 4:33












  • $begingroup$
    You should narrow down your problem though, as it stands, it's too broad. Maybe pick a specific operator (e.g., multiplication).
    $endgroup$
    – parsiad
    Dec 18 '18 at 4:35












  • $begingroup$
    Hmm I see. I've been thinking about mostly convolution or multiplication. In your example above you still don't derive an h(x) for $p(x)?h(x)=g(x)$. I'd like a form where I have both an operator (multiplication or convolution, ideally) and a function that does the transformation h(x).
    $endgroup$
    – regeneration
    Dec 18 '18 at 16:35














0












0








0





$begingroup$

I'm assuming you meant probability density.



You know that
$$
int_{-infty}^{infty}p(x)dx=1.
$$

Using the substitution rule with $x=3y$,
$$
int_{-infty}^{infty}3p(3y)dy=1.
$$

So your "dilated" probability density is $ymapsto3p(3y)$.






share|cite|improve this answer









$endgroup$



I'm assuming you meant probability density.



You know that
$$
int_{-infty}^{infty}p(x)dx=1.
$$

Using the substitution rule with $x=3y$,
$$
int_{-infty}^{infty}3p(3y)dy=1.
$$

So your "dilated" probability density is $ymapsto3p(3y)$.







share|cite|improve this answer












share|cite|improve this answer



share|cite|improve this answer










answered Dec 18 '18 at 2:32









parsiadparsiad

18.3k32453




18.3k32453












  • $begingroup$
    Yes, I mean probability density. To be more clear, I'm looking for a function that can be applied to p(x) directly instead of through substitution (i.e., $p(x) ?h(x)=g(x))$, where ? is some operator and $h(x)$ is some function/distribution. In the shifting example above, the delta function would be h(x).
    $endgroup$
    – regeneration
    Dec 18 '18 at 4:31










  • $begingroup$
    Technically, $G$ defined by $(Gp)(y) = 3p(3y)$ is an operator... ;-)
    $endgroup$
    – parsiad
    Dec 18 '18 at 4:33












  • $begingroup$
    You should narrow down your problem though, as it stands, it's too broad. Maybe pick a specific operator (e.g., multiplication).
    $endgroup$
    – parsiad
    Dec 18 '18 at 4:35












  • $begingroup$
    Hmm I see. I've been thinking about mostly convolution or multiplication. In your example above you still don't derive an h(x) for $p(x)?h(x)=g(x)$. I'd like a form where I have both an operator (multiplication or convolution, ideally) and a function that does the transformation h(x).
    $endgroup$
    – regeneration
    Dec 18 '18 at 16:35


















  • $begingroup$
    Yes, I mean probability density. To be more clear, I'm looking for a function that can be applied to p(x) directly instead of through substitution (i.e., $p(x) ?h(x)=g(x))$, where ? is some operator and $h(x)$ is some function/distribution. In the shifting example above, the delta function would be h(x).
    $endgroup$
    – regeneration
    Dec 18 '18 at 4:31










  • $begingroup$
    Technically, $G$ defined by $(Gp)(y) = 3p(3y)$ is an operator... ;-)
    $endgroup$
    – parsiad
    Dec 18 '18 at 4:33












  • $begingroup$
    You should narrow down your problem though, as it stands, it's too broad. Maybe pick a specific operator (e.g., multiplication).
    $endgroup$
    – parsiad
    Dec 18 '18 at 4:35












  • $begingroup$
    Hmm I see. I've been thinking about mostly convolution or multiplication. In your example above you still don't derive an h(x) for $p(x)?h(x)=g(x)$. I'd like a form where I have both an operator (multiplication or convolution, ideally) and a function that does the transformation h(x).
    $endgroup$
    – regeneration
    Dec 18 '18 at 16:35
















$begingroup$
Yes, I mean probability density. To be more clear, I'm looking for a function that can be applied to p(x) directly instead of through substitution (i.e., $p(x) ?h(x)=g(x))$, where ? is some operator and $h(x)$ is some function/distribution. In the shifting example above, the delta function would be h(x).
$endgroup$
– regeneration
Dec 18 '18 at 4:31




$begingroup$
Yes, I mean probability density. To be more clear, I'm looking for a function that can be applied to p(x) directly instead of through substitution (i.e., $p(x) ?h(x)=g(x))$, where ? is some operator and $h(x)$ is some function/distribution. In the shifting example above, the delta function would be h(x).
$endgroup$
– regeneration
Dec 18 '18 at 4:31












$begingroup$
Technically, $G$ defined by $(Gp)(y) = 3p(3y)$ is an operator... ;-)
$endgroup$
– parsiad
Dec 18 '18 at 4:33






$begingroup$
Technically, $G$ defined by $(Gp)(y) = 3p(3y)$ is an operator... ;-)
$endgroup$
– parsiad
Dec 18 '18 at 4:33














$begingroup$
You should narrow down your problem though, as it stands, it's too broad. Maybe pick a specific operator (e.g., multiplication).
$endgroup$
– parsiad
Dec 18 '18 at 4:35






$begingroup$
You should narrow down your problem though, as it stands, it's too broad. Maybe pick a specific operator (e.g., multiplication).
$endgroup$
– parsiad
Dec 18 '18 at 4:35














$begingroup$
Hmm I see. I've been thinking about mostly convolution or multiplication. In your example above you still don't derive an h(x) for $p(x)?h(x)=g(x)$. I'd like a form where I have both an operator (multiplication or convolution, ideally) and a function that does the transformation h(x).
$endgroup$
– regeneration
Dec 18 '18 at 16:35




$begingroup$
Hmm I see. I've been thinking about mostly convolution or multiplication. In your example above you still don't derive an h(x) for $p(x)?h(x)=g(x)$. I'd like a form where I have both an operator (multiplication or convolution, ideally) and a function that does the transformation h(x).
$endgroup$
– regeneration
Dec 18 '18 at 16:35


















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