optim - setting a common contraint for multiple parameters












1















I a looking to set a common constraint to a subset of my parameters:



c2 <- 2
nFeatures = 6
W2 <- rep(1,nFeatures)
w2 <- W2/sum(W2)
fguess2 <- 0.3
startParms2 <- c(c2,fguess2,w2)
names(startParms2) <- c("c2", "fguess",
"w21","w22","w23","w24","w25","w26")


xout2 <- optim(par=startParms2, fn=rmsd,
data1=mydata2, method = "L-BFGS-B",
lower = rep(0,8),
upper = c(Inf,1,1,1,1,1,1,1))
print(xout2)


Currently, all 6 parameters belonging to the vector w2 are constrained to a individual maximum of 1.
What I would like to do is to constrain the sum of these 6 parameters to 1 (while the remaining 2 parameters keep their current constraints).










share|improve this question

























  • You can encode the constrain into the objective function. Then you will have to optimize only 5 parameters... - However, without a MCVE it is difficult to say more stackoverflow.com/help/mcve

    – Florian
    Nov 24 '18 at 18:15











  • in principle you can use constrOptim(), but I suspect you really are trying to fit a composition parameter (all parameters bound in 0<p<1 and sum(p)==1), in which case you will be better off working with a softmax/Aitchison transformation

    – Ben Bolker
    Nov 26 '18 at 22:44


















1















I a looking to set a common constraint to a subset of my parameters:



c2 <- 2
nFeatures = 6
W2 <- rep(1,nFeatures)
w2 <- W2/sum(W2)
fguess2 <- 0.3
startParms2 <- c(c2,fguess2,w2)
names(startParms2) <- c("c2", "fguess",
"w21","w22","w23","w24","w25","w26")


xout2 <- optim(par=startParms2, fn=rmsd,
data1=mydata2, method = "L-BFGS-B",
lower = rep(0,8),
upper = c(Inf,1,1,1,1,1,1,1))
print(xout2)


Currently, all 6 parameters belonging to the vector w2 are constrained to a individual maximum of 1.
What I would like to do is to constrain the sum of these 6 parameters to 1 (while the remaining 2 parameters keep their current constraints).










share|improve this question

























  • You can encode the constrain into the objective function. Then you will have to optimize only 5 parameters... - However, without a MCVE it is difficult to say more stackoverflow.com/help/mcve

    – Florian
    Nov 24 '18 at 18:15











  • in principle you can use constrOptim(), but I suspect you really are trying to fit a composition parameter (all parameters bound in 0<p<1 and sum(p)==1), in which case you will be better off working with a softmax/Aitchison transformation

    – Ben Bolker
    Nov 26 '18 at 22:44
















1












1








1








I a looking to set a common constraint to a subset of my parameters:



c2 <- 2
nFeatures = 6
W2 <- rep(1,nFeatures)
w2 <- W2/sum(W2)
fguess2 <- 0.3
startParms2 <- c(c2,fguess2,w2)
names(startParms2) <- c("c2", "fguess",
"w21","w22","w23","w24","w25","w26")


xout2 <- optim(par=startParms2, fn=rmsd,
data1=mydata2, method = "L-BFGS-B",
lower = rep(0,8),
upper = c(Inf,1,1,1,1,1,1,1))
print(xout2)


Currently, all 6 parameters belonging to the vector w2 are constrained to a individual maximum of 1.
What I would like to do is to constrain the sum of these 6 parameters to 1 (while the remaining 2 parameters keep their current constraints).










share|improve this question
















I a looking to set a common constraint to a subset of my parameters:



c2 <- 2
nFeatures = 6
W2 <- rep(1,nFeatures)
w2 <- W2/sum(W2)
fguess2 <- 0.3
startParms2 <- c(c2,fguess2,w2)
names(startParms2) <- c("c2", "fguess",
"w21","w22","w23","w24","w25","w26")


xout2 <- optim(par=startParms2, fn=rmsd,
data1=mydata2, method = "L-BFGS-B",
lower = rep(0,8),
upper = c(Inf,1,1,1,1,1,1,1))
print(xout2)


Currently, all 6 parameters belonging to the vector w2 are constrained to a individual maximum of 1.
What I would like to do is to constrain the sum of these 6 parameters to 1 (while the remaining 2 parameters keep their current constraints).







r optimization constraints






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Nov 24 '18 at 18:18









Ben Bolker

133k11223311




133k11223311










asked Nov 24 '18 at 16:54









Moritz TruningerMoritz Truninger

91




91













  • You can encode the constrain into the objective function. Then you will have to optimize only 5 parameters... - However, without a MCVE it is difficult to say more stackoverflow.com/help/mcve

    – Florian
    Nov 24 '18 at 18:15











  • in principle you can use constrOptim(), but I suspect you really are trying to fit a composition parameter (all parameters bound in 0<p<1 and sum(p)==1), in which case you will be better off working with a softmax/Aitchison transformation

    – Ben Bolker
    Nov 26 '18 at 22:44





















  • You can encode the constrain into the objective function. Then you will have to optimize only 5 parameters... - However, without a MCVE it is difficult to say more stackoverflow.com/help/mcve

    – Florian
    Nov 24 '18 at 18:15











  • in principle you can use constrOptim(), but I suspect you really are trying to fit a composition parameter (all parameters bound in 0<p<1 and sum(p)==1), in which case you will be better off working with a softmax/Aitchison transformation

    – Ben Bolker
    Nov 26 '18 at 22:44



















You can encode the constrain into the objective function. Then you will have to optimize only 5 parameters... - However, without a MCVE it is difficult to say more stackoverflow.com/help/mcve

– Florian
Nov 24 '18 at 18:15





You can encode the constrain into the objective function. Then you will have to optimize only 5 parameters... - However, without a MCVE it is difficult to say more stackoverflow.com/help/mcve

– Florian
Nov 24 '18 at 18:15













in principle you can use constrOptim(), but I suspect you really are trying to fit a composition parameter (all parameters bound in 0<p<1 and sum(p)==1), in which case you will be better off working with a softmax/Aitchison transformation

– Ben Bolker
Nov 26 '18 at 22:44







in principle you can use constrOptim(), but I suspect you really are trying to fit a composition parameter (all parameters bound in 0<p<1 and sum(p)==1), in which case you will be better off working with a softmax/Aitchison transformation

– Ben Bolker
Nov 26 '18 at 22:44














0






active

oldest

votes











Your Answer






StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");

StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "1"
};
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',
autoActivateHeartbeat: false,
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
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});


}
});














draft saved

draft discarded


















StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53460384%2foptim-setting-a-common-contraint-for-multiple-parameters%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown

























0






active

oldest

votes








0






active

oldest

votes









active

oldest

votes






active

oldest

votes
















draft saved

draft discarded




















































Thanks for contributing an answer to Stack Overflow!


  • 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%2fstackoverflow.com%2fquestions%2f53460384%2foptim-setting-a-common-contraint-for-multiple-parameters%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

Contact image not getting when fetch all contact list from iPhone by CNContact

count number of partitions of a set with n elements into k subsets

A CLEAN and SIMPLE way to add appendices to Table of Contents and bookmarks