Problems dealing with matrices

Hi Halim,

For the first two questions, you may try:
colsum1 <- colSums(volyrdc1)
min(which(colsum1>=18))
#[1] 29
#or
?head(which(colsum1>=18),1)
#140 
# 29?

colsum1[substr(colsum1,6,7)=="00"]? ## this is not very clear
???? 305 
45.37004?
#or
colsum1[colsum1>=18][substr(colsum1[colsum1>=18],6,7)=="00"]
???? 305 
45.37004

#because
sprintf("%.4f",colsum1[colsum1>=18])
colsum1[colsum1>=18][gsub(".*\\.\\d{2}","",sprintf("%.4f",
colsum1[colsum1>=18]))=="00"] ???? 180????? 305 
32.88996 45.37004

A.K.

On Thursday, November 28, 2013 3:57 AM, halim10-fes <halim10-
fes at sust.edu> wrote: Hi,

Sorry for continuous bothering. Continuum of the previous problem...

I have the following matrices and vectors,

dcmat<-matrix(c(0.13,0.61,0.25,0.00,0.00,0.00,0.52,0.37,0.09,0.00,
0.00,0.00, ? ? ? ? ? ? ? ? 0.58,0.30,0.11,0.00,0.00,0.00,0.46,0.22,
0.00,0.00,0.00,0.00, ? ? ? ? ? ? ? ? 0.09),nrow=5,ncol=5)

volini<-matrix(c(0,0,0,0,0),nrow=5,ncol=1)

volinp1<-c(0, 0.0004669094, 0.0027610861, 0.0086204692, 0.0200137754, 
0.0389069106 ,0.0670942588, 0.1060941424, 0.1570990708, 0.2209672605, 
0.2982420945, 0.3891882830, 0.4938361307, 0.6120278338, 0.7434618363, 
0.8877329008, 1.0443667375, 1.2128488387, 1.3926476912, 1.5832328410, 
1.7840884399, 1.9947229566, 2.2146757191, 2.4435209092, 2.6808695568, 
2.9263700050, 3.1797072430, 3.4406014299, 3.7088058696, 3.9841046430, 
4.2663100561, 4.5552600226, 4.8508154713, 5.1528578389, 5.4612866929,
5.7760175114, 6.0969796345, 6.4241143947, 6.7573734248, 7, 7 ,7, 7,
? 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
? 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
? 7, 7, 7, 7, 7, 7, 7, 7,? 7,? 7, 7, 7)

I've calculated the following matrices vol and volyrdc1 (obviously 
with the help of Jeff and Arun):

#Blank matrices for dumping final values

vol <- matrix( NA, nrow=5, ncol=length(volinp1))

volyrdc1<-matrix(NA, nrow=5,ncol=length(volinp1),dimnames= 
list(c("DC1","DC2","DC3","DC4","DC5"),c(seq(0,500,5))))

vol[ , 1 ] <- dcmat %*% (volini+(volinp1[1]*wt))

wt<-matrix(c(1,0,0,0,0),nrow=5)

for ( idx in seq_along(volinp1)[ -1 ] ) { 
? vol[ , idx ] <- dcmat %*% ( vol[ , idx-1 ] + volinp1[idx] * wt ) 
}?

vol

volyrdc1[,1]<-vol[,1]

for ( idx in seq_along(volinp1)[ -1 ] ) { 
? volyrdc1[ , idx ] <- vol[ , idx-1 ] + volinp1[idx] * wt
? }? 
volyrdc1

My final matrix in 'volyrdc1' (kind of transition matrix model).

Now, what I want to do is to calculate when the colsum<-
colSums(volyrdc1) reaches a certain value and I want to get the 
index of the element in the 'colsum' vector at that point. For e.g. 
when colsum[colsum>=18] ? It will give a series of cases where the 
condition is true. But I want index of the element immediately when 
the condition is met. In this case, the answer I want is 140 
(colsum[29] returns both value (18.63) and the character ("140") 
attributing the index). Actually, in my case 140 is year (age) when 
the 'colsum' becomes 

=18. At is point it would be great if I can calculate when 'colsum' levels 

off (up to two decimal place)? The answer is: 305 and at that point 
colsum==45.37.?

I also want to calculate what should be the value in volini[1,1] to 
get a certain value in 'colsum' at a certain year (age)(vector 
element index explained earlier)? For e.g. I want to find out that 
what should be the value in volini[1,1] if I want colsum==18 at 
100(charater attributing colsum[21])? The answer is: 15910 and the 
'volini' matrix will look like:

volini<-matrix(c(15910,0,0,0,0),nrow=5,ncol=1)

Any pointer, suggestions,... will be gratefully acknowledged.

P.S. Can you please suggest me any effective R programming book that 
describe core elements of R programming?

Thanks in advance.

Regards,

Halim? ? ? ? ? ? ? ? 
---------------
Md. Abdul Halim
Assistant Professor
Department of Forestry and Environmental Science
Shahjalal University of Science and Technology,Sylhet-3114,
Bangladesh.
Cell: +8801714078386.
alt. e-mail: xou03 at yahoo.com

On Tue, 26 Nov 2013 20:21:14 -0800 (PST), arun wrote

HI Halim,

No problem.
Regards,
Arun

On Tuesday, November 26, 2013 11:18 PM, halim10-fes <halim10-
fes at sust.edu> wrote: Hi Arun,

Thanks for your help. Sorry for my late response. Take care and stay 
fine.

Regards,

Halim

On Sun, 24 Nov 2013 07:45:24 -0800 (PST), arun wrote

Hi Halim,
I guess this works for you.? Modifying Jeff's solution:

volinp<-c(0,0.000467,0.002762,0.008621,0.020014,0.038907,0.067094)
vol1 <- dcmat %*% (volmat +wt)
for(idx in seq_along(volinp)[-1]){
?vol1 <- cbind(vol1,dcmat %*% (vol1[,idx-1] + volinp[idx] *wt))
?}

#or

vol <- matrix( NA, nrow=5, ncol=length( volinp ) )
vol[ , 1 ] <- dcmat %*% ( volmat + wt )

for ( idx in seq_along(volinp)[ -1 ] ) {
? vol[ , idx ] <- dcmat %*% ( vol[ , idx-1 ] + volinp[idx] * wt )
}
identical(vol,vol1)
#[1] TRUE

A.K.

On Sunday, November 24, 2013 7:16 AM, halim10-fes <halim10-
fes at sust.edu> wrote: Hi Arun,

OK, no problem. Thank you very much for your attention. I've posted 
an annex to my previous problem. I will appreciate your 
comments/suggestions on it.

Off-topic: You're a very helpful man. I like your attitude to 
helping others.

Take care.

Halim

On Sun, 24 Nov 2013 01:18:18 -0800 (PST), arun wrote

Hi,
Please disregard my earlier message. Looks like Jeff understand it 
better and answered it. Regards, Arun

On Sunday, November 24, 2013 3:23 AM, arun <smartpink111 at yahoo.com> 

wrote:

Hi,
I am finding some inconsistency with your description.
For example:
volinp[1]+volmat[1,1]
[1] 101

On Sunday, November 24, 2013 1:52 AM, halim10-fes <halim10-
fes at sust.edu> wrote:

Please apologize me! Earlier I've sent a message erroneously. 
Following is the original problem for which I'm seeking help. 
Extremely sorry...?

Hi Arun,

Thank you very much for your response. Sorry, if I couldn't explain 
clearly. I think, I should restate the problem to get exactly what I 
want. Here it goes:

I have 2 matrices and 1 vector, namely,

dcmat<-matrix(c(0.13,0.61,0.25,0.00,0.00,0.00,0.52,0.37,0.09,0.00,
0.00,0.00, ? ? ? ? ? ? ? ? 0.58,0.30,0.11,0.00,0.00,0.00,0.46,0.22,
0.00,0.00,0.00,0.00, ? ? ? ? ? ? ? ? 0.09),nrow=5,ncol=5)

volmat<-matrix(c(100,0,0,0,0),nrow=5,ncol=1)

volinp<-c(1:40)

What I essentially want to do is to multiply 'dcmat' with 'volmat' 
and dump the output in a new matrix 'vol'. But before that, in the 
first step, I want to add volinp[1] with volmat[1,1]. So, the first 
column of the output matrix 'vol' matrix will be:

? ? ? ? [,1]
[1,]?? 13.13
[2,]?? 61.61
[3,]?? 25.25
[4,]? ? 0.00
[5,]? ? 0.00

In the 2nd step, I want to replace 'volmat' with vol[,1] and add 
volinp[2] with vol[1,1]. The new 'volmat' will look like:

? ? ? ? [,1]
[1,]?? 15.13
[2,]?? 61.61
[3,]?? 25.25
[4,]? ? 0.00
[5,]? ? 0.00

Then multiply 'dcmat' with the new 'volmat', and the 2nd column of 
output matrix 'vol' will look like:

? ? ? ? [,2]
[1,]? 1.9669
[2,] 41.2665
[3,] 41.2232
[4,] 13.1199
[5,]? 2.7775

Then again, replace the 'volmat' with vol[,2], add volinp[3] with 
vol[1,2] and multiply the new 'volmat' with 'dcmat'. This 
replacement, addition, multiplication, and dumping will continue up 
to the length of 'volinp' and the final output matrix 'vol' will be 
something like:

? ? ? [,1]? ? [,2]? ? ? [,3]? ? ...length(volinp)
[1,] 13.13?? 1.9669?? 0.645697? ...
[2,] 61.61? 41.2665? 24.488389? ...
[3,] 25.25? 41.2232? 40.419786? ...
[4,]? 0.00? 13.1199? 22.116099? ...
[5,]? 0.00?? 2.7775?? 7.670905? ...?

Within my limited capacity, I've tried to come up with a solution 
but failed.

I'll appreciate your/others' help with gratefulness.

Regards,

Halim

---------------
Md. Abdul Halim
Assistant Professor
Department of Forestry and Environmental Science
Shahjalal University of Science and Technology,Sylhet-3114,
Bangladesh.
Cell: +8801714078386.
alt. e-mail: xou03 at yahoo.com

On Sat, 23 Nov 2013 14:10:12 -0800 (PST), arun wrote

Hi,
Could you show your expected output?? It is a bit unclear from the 

description.

On Saturday, November 23, 2013 2:00 PM, halim10-fes <halim10-
fes at sust.edu> wrote: Dear R-friends,

Hope you doing well. I've been trying to deal with the following 
problem for the couple of days but couldn't come up with a solution. 
It would be great if any of you could give some insight into it.

I have three matrices like:

dcvol<-matrix(c(0.13,0.61,0.25,0.00,0.00,0.00,0.52,0.37,0.09,0.00,
0.00,0.00, ? ? ? ? ? ? ? ? 0.58,0.30,0.11,0.00,0.00,0.00,0.46,0.22,
0.00,0.00,0.00,0.00, ? ? ? ? ? ? ? ? 0.09),nrow=5,ncol=5) 

volinp<-

matrix(c(100,0,0,0,0),nrow=5,ncol=1)

scvol<-matrix(c(1:40),nrow=5,ncol=8)

What I essentially want to do is to add each value in scvol[1,] with 
the volinp[1,1] and then multiply each new volinp with dcvol and 
finally put the outputs in a new matrix.

Thanks in advance.

Halim? ? ? ? ? ? ? ? 
---------------
Md. Abdul Halim
Assistant Professor
Department of Forestry and Environmental Science
Shahjalal University of Science and Technology,Sylhet-3114,
Bangladesh.
Cell: +8801714078386.
alt. e-mail: xou03 at yahoo.com

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Md. Abdul Halim
Assistant Professor
Department of Forestry and Environmental Science
Shahjalal University of Science and Technology,Sylhet-3114,
Bangladesh.
Cell: +8801714078386.
alt. e-mail: xou03 at yahoo.com

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---------------
Md. Abdul Halim
Assistant Professor
Department of Forestry and Environmental Science
Shahjalal University of Science and Technology,Sylhet-3114,
Bangladesh.
Cell: +8801714078386.
alt. e-mail: xou03 at yahoo.com

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---------------
Md. Abdul Halim
Assistant Professor
Department of Forestry and Environmental Science
Shahjalal University of Science and Technology,Sylhet-3114,
Bangladesh.
Cell: +8801714078386.
alt. e-mail: xou03 at yahoo.com

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