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#51 Re: Help Me ! » difference between pdf and accumulative frequency ? » 2012-02-01 23:12:59

model
bobbym wrote:

Hi model;

and total probability is
2/5+ 4/5 + 5 /5 =  2.2

Let me help you out here. A probability can never be greater than 1. So what are we computing here?

ohh yes . the same question i have .
I do't  know but i read out the formula of combination for finding probability  from book.

#52 Re: Help Me ! » difference between pdf and accumulative frequency ? » 2012-02-01 23:10:40

model

if yes then I have another formula for Binomial probability

Pr(X= r) = nCr(p^r)q^(n-r)   where n and p are binomial  parameters and q = i-p .

What is the purpose of this  ?
What is the actual meaning of that ?
Is combination not just enough for finding  probability ?

#53 Re: Help Me ! » difference between pdf and accumulative frequency ? » 2012-02-01 23:02:56

model
bobbym wrote:

Hi;

to chose 2 times out of 3.
nCr(2,3) = 3! /2! (3-2)!

Hold it for a second. Not nitpicking here but we have to speak the same language if we are going to communicate.

Ncr(3,2) means 3 choose 2. From 3 objects choose 2 of them. Ncr(2,3) means 2 choose 3 which can not be done and equals 0.

ohh sorry i wrote is wrong.
but anyways , logically the probability from combination and the way  that i did for histogram of  some  pixels .

Logically both have same meaning . Right ?

#54 Re: Help Me ! » Bayes' Theorem » 2012-02-01 23:00:52

model
MathsIsFun wrote:

thanks for the  link . smile

#55 Re: Help Me ! » conditional probability » 2012-02-01 22:59:51

model

ohh cool Thanks Bob from me too . smile

#56 Re: Help Me ! » difference between pdf and accumulative frequency ? » 2012-02-01 22:55:38

model

hmm yes ..

Example of binomial random variable :
How many ways are there to chose 2 times out of 3.
nCr(2,3) = 3! /2! (3-2)!

The above way is called combination .

Now suppose we have some values or pixels values like

pixels    frequency                         accumulative frequency   
1             1 is repeated  2 times               2
1               2 is repeated 2 times              4
2             3 is repeated 1 time                 5
3             
2



and total probability is
2/5+ 4/5 + 5 /5 =  2.2

#57 Re: Help Me ! » difference between pdf and accumulative frequency ? » 2012-02-01 22:42:34

model

Hy one second,

I read out  binomial random variables can be solved from combination nC(r) for finding the probability and i successfully represented probabilities in form of histogram .

On the other hand, I maked histogram of some pixels using this way .

Data : i have pixel values ./
frequency : the repetition of pixel values
Accumulative frequency : add current and previous frequency .
probability :  divide each accumulative frequency  by total number of data or class interval  width .

Now My question is  combination and the other way  that i explained .  both are same logically .
Right ?

#58 Re: Help Me ! » Bayes' Theorem » 2012-02-01 19:39:58

model

Hy ,

17078 is my question thread . and where is diagram as  you  said in your posted reply ?

#59 Help Me ! » difference between pdf and accumulative frequency ? » 2012-02-01 19:35:59

model
Replies: 36

Are probability density  function and accumulative frequency same thing ?

#60 Help Me ! » Bayes' Theorem » 2012-01-31 19:47:41

model
Replies: 25

Hy guys ,

I did not understand the basic meaning and purpose of Bayes' Theorem . Could any one please elaborate a bit .
Thanks

#61 Re: Help Me ! » angle inversion problem when moved to up or down side » 2012-01-06 20:16:35

model

hy Bob,

but i did the same .
I have current and previous position with x and y .
so just calculated deltaX = x2 - x1 and deltay = y2 - y1
  double angle = arctanDegree( deltaY ,deltaX );
and i have converted  it in degree, too .

Is that not same as you  said ,

#62 Help Me ! » angle inversion problem when moved to up or down side » 2012-01-06 00:15:21

model
Replies: 3

hy All,

I calculated angle . but when i move to up side . My angle inverted  and show  direction to down side .

and when i move to down side . my angle direction showed to upside .  So  angle is inverted .

Does any one have idea how to solve this angle inversion problem .
Thanks

#63 Help Me ! » Speed and distance » 2012-01-04 18:34:58

model
Replies: 0

Hy All,

I am trying to detect fast , slow  and running objects in the video .

I  have calculated distance between current and previous position.
so  based on  distance i detected slow . and fast and running object s /like in my work show  that

if dis < 10 and dis > 0 --> crawling
else if dis > 10 and dis < 70 --> fast 
else --> object is running .

and when i calculated speed  which is tooo small either object is in slow speed or fast speed . Its  near to 0.0454523 or 1.02424
or 2.54545 but if object run then speed showed by my program is near  to 11 ..

Its  too small  either object  run , slow or fast .
So Please tell me what is the purpose of calculating the speed which  is = distance / time .

after calculating  the speed i realize  that its useless .

Please guide me Thanks

#64 Re: Help Me ! » slow and fast speed calculation » 2011-12-30 21:16:32

model

ah you meant do calculation in double but show  your  ans in int form by  casting double to int .

I see.. ok Thanks Bob . smile

#65 Re: Help Me ! » slow and fast speed calculation » 2011-12-29 00:18:24

model

Hy Bob ,

if floating point i meant double is best to use then how  to get rid from  very  large and very small numbers  ???

#66 Re: Help Me ! » slow and fast speed calculation » 2011-12-29 00:15:34

model

since i am using double for speed and distance . and  this  output
Distance : 1.1219e+006
speed :47.1996 

is terrible or not  understandable specially for me .
so i want  the output that user should easy to understand . and also should work for my project requirement .

#67 Re: Help Me ! » slow and fast speed calculation » 2011-12-28 22:01:27

model

yes .. I  want output in more readable or  understandable  form for user .

#68 Re: Help Me ! » slow and fast speed calculation » 2011-12-27 13:32:21

model

I  am using c++

#69 Re: Help Me ! » slow and fast speed calculation » 2011-12-27 07:15:31

model

yes so  i think i should try to handle very large and very small numbers .  but any idea how  ?

#70 Help Me ! » slow and fast speed calculation » 2011-12-27 04:00:31

model
Replies: 10

Hy  all ,

Since i am trying to detect slow and  fast motion of  my moving object . ,Conceptually , When i move  slow  then my current and previous motion almost about  near ,., not much difference  ... so probably less difference and speed  would be low . .

but if i move fast  then more distance  will cover at the same  time . so speed  will be more .

But some time i get distance  some thing like

get this value

Distance : 1.1219e+006
speed :47.1996
Distance : 1.1219e+006
speed :47.1996
Distance : 1.1219e+006
speed :47.1996
Distance : 1.1219e+006
speed :47.1996
Distance : 1.1219e+006
speed :47.1996

i do't understand this reason .

any one could guide me please thanks

#71 Help Me ! » compactness and non- compactness of objects » 2011-12-20 21:52:40

model
Replies: 2

What does mean by compactness ?

There  is image : http://imageshack.us/photo/my-images/190/42484776.png/

In the image , 1st figure shows the  compactness whose value is less may be 1 or 0.754 some thing .

Note : according to the  1st  figure as circle  presented in the image .
that shows more thickness and compact  and while in the 2nd figure , it shows less compact and more thicknesss

What does that mean actually . Compactness is based on what thing ? ?

Please clear this concept thanks

#72 Re: Help Me ! » boundary in complex plane » 2011-12-20 21:41:47

model

Hi Bob , I like that . i meant your message .

Bob, I am reading book and have seminar so present this all.
Well , now my seminar is going to start so let see what happen . and my ans to the above question is ellipse . because eccentricity  of circle is 0 . so we can't approximate  boundary of complex numbers as a  circle .

#73 Re: Help Me ! » boundary in complex plane » 2011-12-20 13:21:59

model

well,  we  can represent the boundary  of complex plane as a circle ?
no ??  if  yes  then why in the above statement he said  ellipse /

#74 Help Me ! » normalization » 2011-12-20 13:19:11

model
Replies: 2

what does mean by normalization .

like ( sum of  all values )/total  number of points .

That mean normalization . what does that mean ?
can some one tell me via vitalization about  normalization refer to what thing ?

#75 Re: Help Me ! » Fourier Descriptors : reduce 2D to 1D problem .How ? » 2011-12-20 06:49:36

model

Well i came to know that

My 1st  question'  ans :
1D Function : weighted sum of many different complex exponents
So rotated image is may be difficult to recognize . while in 1D  since Fourier descriptor as  1D ( i-e weighted sum of different complex  exponent and DC == average  sum of points  ) that mean rotated or scaling will not effect in recognizing the image.  so problem solved from 2D  to 1D  as  a function .

So smaller the fourier co-efficient : lose of details and global  shape of boundary  of an object .
higher the Fourier co-efficient : more details and high frequency  components .

So  less Fourier descriptor , loss of details  but  since " The boundary in the complex plane is approximated by an ellipse with minimum Fourier descriptor 2 . Although resultant shape will be lose of details but approximated  to original  shape .
As  a result , Fourier descriptors are invariant to scaling  and rotation.

yes , last figure shown in the linked image ,retain the original shape
because boundary in complex numbers  are approximated to an ellipse ( but why ellipse may be because circle have no boundary  and after circle we get ellipse ; )

That's  all my thinking and understanding ,.
and i do't know more  than that

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