Optimising for Scalability












-1














I have working code in R. I want to optimise it. At the moment I am inverting the matrix using Cholesky decomposition.



X<- matrix(rnorm(10000),20,20)
Y<-rnorm(20)

OSLOG<-function(X,Y,a){
if(a<=0){
print("a must be a positive number")
}else{
X<-as.matrix(X)
Y<-as.matrix(Y)
T<-nrow(X)
N<-ncol(X)
bt<- matrix(0,ncol=1,nrow=N)
At<- diag(0,N)
pred<- matrix(0,nrow=T,ncol=1)
theta0<- rep(1,N)
for (t in 1:T){
xt<-X[t,]
pred[t] <- crossprod(as.matrix(theta0), xt)
Dt <- diag(sqrt(abs(c(theta0))))
D <- outer(diag(Dt),diag(Dt))
At <- At + tcrossprod(xt,xt)
InvA <- chol2inv(chol(diag(a,N) + At*D))
bt <- bt + (Y[t] * xt)
theta0 <- crossprod(InvA *D,bt)
}
res<-postResample(pred = pred, obs = Y)
stats<- as.matrix(res)
quant<-quantile(as.matrix(Y)-as.matrix(pred),probs=c(.25,.50,.75))
return(list(predictions=pred,performance=stats,quantiles=quant))
}
}
OSLOG(X,Y,0.00001)$performance


The above code works perfectly well. Is it possible to use Sharman-Morrison in the above code? Also, any other thing I can do to improve performance?



I tried to improve the performance by using Sharman Morrison inversion. For some reason, I don't get the same result.



By replacing initialisation, InvA in the above code by the following



InvA <- At +  tcrossprod(xt,xt) 
InvA <- InvA - (tcrossprod(crossprod(InvA ,xt),crossprod(InvA,xt)) / as.numeric(crossprod(xt,crossprod(InvA,xt))+1))


where initialisation is At<- diag(1/a,N), but doing so gives a different result. Can someone help me with this, please?










share|improve this question









New contributor




Jamil is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.




















  • Welcome to Code Review! Unfortunately this post is off-topic for this site. Please read What topics can I ask about here? - note that it states "If you are looking for feedback on a specific working piece of code...then you are in the right place!" Also, when posting your question, there should have been text on the side that read "Your question must contain code that is already working correctly..." When you have fixed the code, please update it here and it can be reviewed."
    – Sᴀᴍ Onᴇᴌᴀ
    1 hour ago










  • The code is working! I am just trying to optimise the code which is clearly on topic. I have updated the question hope it is more clear now.
    – Jamil
    1 hour ago


















-1














I have working code in R. I want to optimise it. At the moment I am inverting the matrix using Cholesky decomposition.



X<- matrix(rnorm(10000),20,20)
Y<-rnorm(20)

OSLOG<-function(X,Y,a){
if(a<=0){
print("a must be a positive number")
}else{
X<-as.matrix(X)
Y<-as.matrix(Y)
T<-nrow(X)
N<-ncol(X)
bt<- matrix(0,ncol=1,nrow=N)
At<- diag(0,N)
pred<- matrix(0,nrow=T,ncol=1)
theta0<- rep(1,N)
for (t in 1:T){
xt<-X[t,]
pred[t] <- crossprod(as.matrix(theta0), xt)
Dt <- diag(sqrt(abs(c(theta0))))
D <- outer(diag(Dt),diag(Dt))
At <- At + tcrossprod(xt,xt)
InvA <- chol2inv(chol(diag(a,N) + At*D))
bt <- bt + (Y[t] * xt)
theta0 <- crossprod(InvA *D,bt)
}
res<-postResample(pred = pred, obs = Y)
stats<- as.matrix(res)
quant<-quantile(as.matrix(Y)-as.matrix(pred),probs=c(.25,.50,.75))
return(list(predictions=pred,performance=stats,quantiles=quant))
}
}
OSLOG(X,Y,0.00001)$performance


The above code works perfectly well. Is it possible to use Sharman-Morrison in the above code? Also, any other thing I can do to improve performance?



I tried to improve the performance by using Sharman Morrison inversion. For some reason, I don't get the same result.



By replacing initialisation, InvA in the above code by the following



InvA <- At +  tcrossprod(xt,xt) 
InvA <- InvA - (tcrossprod(crossprod(InvA ,xt),crossprod(InvA,xt)) / as.numeric(crossprod(xt,crossprod(InvA,xt))+1))


where initialisation is At<- diag(1/a,N), but doing so gives a different result. Can someone help me with this, please?










share|improve this question









New contributor




Jamil is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.




















  • Welcome to Code Review! Unfortunately this post is off-topic for this site. Please read What topics can I ask about here? - note that it states "If you are looking for feedback on a specific working piece of code...then you are in the right place!" Also, when posting your question, there should have been text on the side that read "Your question must contain code that is already working correctly..." When you have fixed the code, please update it here and it can be reviewed."
    – Sᴀᴍ Onᴇᴌᴀ
    1 hour ago










  • The code is working! I am just trying to optimise the code which is clearly on topic. I have updated the question hope it is more clear now.
    – Jamil
    1 hour ago
















-1












-1








-1







I have working code in R. I want to optimise it. At the moment I am inverting the matrix using Cholesky decomposition.



X<- matrix(rnorm(10000),20,20)
Y<-rnorm(20)

OSLOG<-function(X,Y,a){
if(a<=0){
print("a must be a positive number")
}else{
X<-as.matrix(X)
Y<-as.matrix(Y)
T<-nrow(X)
N<-ncol(X)
bt<- matrix(0,ncol=1,nrow=N)
At<- diag(0,N)
pred<- matrix(0,nrow=T,ncol=1)
theta0<- rep(1,N)
for (t in 1:T){
xt<-X[t,]
pred[t] <- crossprod(as.matrix(theta0), xt)
Dt <- diag(sqrt(abs(c(theta0))))
D <- outer(diag(Dt),diag(Dt))
At <- At + tcrossprod(xt,xt)
InvA <- chol2inv(chol(diag(a,N) + At*D))
bt <- bt + (Y[t] * xt)
theta0 <- crossprod(InvA *D,bt)
}
res<-postResample(pred = pred, obs = Y)
stats<- as.matrix(res)
quant<-quantile(as.matrix(Y)-as.matrix(pred),probs=c(.25,.50,.75))
return(list(predictions=pred,performance=stats,quantiles=quant))
}
}
OSLOG(X,Y,0.00001)$performance


The above code works perfectly well. Is it possible to use Sharman-Morrison in the above code? Also, any other thing I can do to improve performance?



I tried to improve the performance by using Sharman Morrison inversion. For some reason, I don't get the same result.



By replacing initialisation, InvA in the above code by the following



InvA <- At +  tcrossprod(xt,xt) 
InvA <- InvA - (tcrossprod(crossprod(InvA ,xt),crossprod(InvA,xt)) / as.numeric(crossprod(xt,crossprod(InvA,xt))+1))


where initialisation is At<- diag(1/a,N), but doing so gives a different result. Can someone help me with this, please?










share|improve this question









New contributor




Jamil is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











I have working code in R. I want to optimise it. At the moment I am inverting the matrix using Cholesky decomposition.



X<- matrix(rnorm(10000),20,20)
Y<-rnorm(20)

OSLOG<-function(X,Y,a){
if(a<=0){
print("a must be a positive number")
}else{
X<-as.matrix(X)
Y<-as.matrix(Y)
T<-nrow(X)
N<-ncol(X)
bt<- matrix(0,ncol=1,nrow=N)
At<- diag(0,N)
pred<- matrix(0,nrow=T,ncol=1)
theta0<- rep(1,N)
for (t in 1:T){
xt<-X[t,]
pred[t] <- crossprod(as.matrix(theta0), xt)
Dt <- diag(sqrt(abs(c(theta0))))
D <- outer(diag(Dt),diag(Dt))
At <- At + tcrossprod(xt,xt)
InvA <- chol2inv(chol(diag(a,N) + At*D))
bt <- bt + (Y[t] * xt)
theta0 <- crossprod(InvA *D,bt)
}
res<-postResample(pred = pred, obs = Y)
stats<- as.matrix(res)
quant<-quantile(as.matrix(Y)-as.matrix(pred),probs=c(.25,.50,.75))
return(list(predictions=pred,performance=stats,quantiles=quant))
}
}
OSLOG(X,Y,0.00001)$performance


The above code works perfectly well. Is it possible to use Sharman-Morrison in the above code? Also, any other thing I can do to improve performance?



I tried to improve the performance by using Sharman Morrison inversion. For some reason, I don't get the same result.



By replacing initialisation, InvA in the above code by the following



InvA <- At +  tcrossprod(xt,xt) 
InvA <- InvA - (tcrossprod(crossprod(InvA ,xt),crossprod(InvA,xt)) / as.numeric(crossprod(xt,crossprod(InvA,xt))+1))


where initialisation is At<- diag(1/a,N), but doing so gives a different result. Can someone help me with this, please?







performance r






share|improve this question









New contributor




Jamil is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











share|improve this question









New contributor




Jamil is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









share|improve this question




share|improve this question








edited 8 mins ago





















New contributor




Jamil is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









asked 1 hour ago









Jamil

11




11




New contributor




Jamil is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.





New contributor





Jamil is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.






Jamil is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.












  • Welcome to Code Review! Unfortunately this post is off-topic for this site. Please read What topics can I ask about here? - note that it states "If you are looking for feedback on a specific working piece of code...then you are in the right place!" Also, when posting your question, there should have been text on the side that read "Your question must contain code that is already working correctly..." When you have fixed the code, please update it here and it can be reviewed."
    – Sᴀᴍ Onᴇᴌᴀ
    1 hour ago










  • The code is working! I am just trying to optimise the code which is clearly on topic. I have updated the question hope it is more clear now.
    – Jamil
    1 hour ago




















  • Welcome to Code Review! Unfortunately this post is off-topic for this site. Please read What topics can I ask about here? - note that it states "If you are looking for feedback on a specific working piece of code...then you are in the right place!" Also, when posting your question, there should have been text on the side that read "Your question must contain code that is already working correctly..." When you have fixed the code, please update it here and it can be reviewed."
    – Sᴀᴍ Onᴇᴌᴀ
    1 hour ago










  • The code is working! I am just trying to optimise the code which is clearly on topic. I have updated the question hope it is more clear now.
    – Jamil
    1 hour ago


















Welcome to Code Review! Unfortunately this post is off-topic for this site. Please read What topics can I ask about here? - note that it states "If you are looking for feedback on a specific working piece of code...then you are in the right place!" Also, when posting your question, there should have been text on the side that read "Your question must contain code that is already working correctly..." When you have fixed the code, please update it here and it can be reviewed."
– Sᴀᴍ Onᴇᴌᴀ
1 hour ago




Welcome to Code Review! Unfortunately this post is off-topic for this site. Please read What topics can I ask about here? - note that it states "If you are looking for feedback on a specific working piece of code...then you are in the right place!" Also, when posting your question, there should have been text on the side that read "Your question must contain code that is already working correctly..." When you have fixed the code, please update it here and it can be reviewed."
– Sᴀᴍ Onᴇᴌᴀ
1 hour ago












The code is working! I am just trying to optimise the code which is clearly on topic. I have updated the question hope it is more clear now.
– Jamil
1 hour ago






The code is working! I am just trying to optimise the code which is clearly on topic. I have updated the question hope it is more clear now.
– Jamil
1 hour ago

















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