avoiding expression evaluation when calling a function

Hey thanks, that worked. So you're right, I'd like to run it for multiple
values of i. As it's written, I'm doing it in a for loop, as

plotter<-function(i,fram,framvec,obj,form1,form2){
 temp.i<-fram[framvec <=(i*.10),]
plot(form1, data=temp.i, xlim=c(0,1500), ylim=c(0,35), main=(i*.10))
 mod<-lm(form2,data=temp.i)
r2<-summary(mod)$adj.r.squared
rsqrd[i]<-r2
 legend("bottomright", legend=signif(r2), col="black")
abline(mod)
 rsqrd
}
for(i in 0:10){
  rsqrd<-plotter(i,fram,framvec,obj,form1,form2 )
}
plot(rsqrd)
abline(lm(rsqrd~c(1:10)))

i tried using your suggestion for lapply, but don't fully understand that
function (even after reading the help file).

rrsqrd <- lapply(1:10, function(my.i)
plotter(i=my.i,fram=rwb,framvec=rwb$prcnt.char.depth,obj=prcnt.char.depth,form1=
post.f.crwn.length~leaf.area,form2=post.f.crwn.length~leaf.area-1))

This must be doing something in the background I can't see, though,
because
it took my computer a few seconds to run the first time, and locked it up
for a couple minutes the second.

If anyone cares to explain, thanks - otherwise I'll limp along with my old
for loop.

Best

On Fri, Mar 30, 2012 at 12:42 PM, Joshua Wiley &lt;jwiley.psych@&gt;wrote:

Hi Benjamin,

See inline

On Fri, Mar 30, 2012 at 12:31 PM, Benjamin Caldwell
<btcaldwell@> wrote:

Another question on functions - I have something that looks like

plotter<-function(i){
temp.i<-rwb[rwb$vector1 <=(i*.10),]
 with(temp.i, plot(vector2, vector3, main=(i*.10),))
mod<-lm(vector3~vector3-1,data=temp.i)
 r2<-summary(mod)$adj.r.squared
rsqrd[i]<-r2
legend("bottomright", legend=signif(r2), col="black")
 abline(mod)
rsqrd<<-rsqrd
}


I'd rather not have to go into the function and re-type each vector and
dataframe as I apply it to different vectors. My idea is something

like:

Close, but pass a formula object.  Something like (untested)


plotter <- function(i, frm, obj, form){
 temp.i<-frm[frm$obj <=(i*.10),]
 plot(form, main=(i*.10), data = temp.i)
 mod<-lm(form, data=temp.i)
 r2<-summary(mod)$adj.r.squared
  legend("bottomright", legend=signif(r2), col="black")
 abline(mod)
 return(rsqrd)
}

and I guess you are doing this for different values of i? so maybe


rsqrd <- lapply(1:100, function(my.i) plotter(i = my.i, frm =
your_frm, obj = your_obj, form = y ~ x))

Hope this helps,

Josh

plotter<-function(i,frm,obj,x,y){
 temp.i<-frm[frm$obj <=(i*.10),]
with(temp.i, plot(x, y, main=(i*.10),))
 mod<-lm(y~x-1,data=temp.i)
r2<-summary(mod)$adj.r.squared
rsqrd[i]<-r2
 legend("bottomright", legend=signif(r2), col="black")
abline(mod)
 rsqrd<<-rsqrd
}

However, it seems that when I do this the function is calling x, y from

the

global environment rather than simply passing the text and using the

frame

temp.i I create in the function. One idea I had was to go from read.csv

to

frm, obj entirely within the function, but that's about 110 lines of

code

each time.

I'm hoping there's a way to have some of the expressions passed within

the

function without evaluation, in this case without calling data from the
global environment.

I've tried substitute(),

plotter<-function(i,frm,obj,x,y){
temp.i<-frm[frm$obj <=(i*.10),]
with(temp.i, plot(substitute(x), substitute(y), xlim=c(0,250),
ylim=c(0,35), main=(i*.10),))
 mod<-lm(substitute(y)~substitute(x)-1,data=temp.i)
r2<-summary(mod)$adj.r.squared
 rsqrd[i]<-r2
legend("bottomright", legend=signif(r2), col="black")
 abline(mod)
rsqrd<<-rsqrd
}
but am told "cannot coerce type 'symbol' to vector of type 'double'"


Any suggestions appreciated.

Thanks

Ben

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