y**3
发帖数: 267 | 1 help needed from sas expert!
I have 2 variables in my sas data set-var1 var2. var2 only has value at the
first record.i need to compute the rest of var2 based on the ratios of two
records next to each other; for ex;
the 2nd row ; var22=(95/87)*85; then compute var23 based on the new number
and var12 and var13.
how to code this in sas efficiently? thanks
var1 var2
87 95
85
78
75
65
56
34 |
a******r
发帖数: 8 | 2 data new;
set old;
if (_n_ EQ 1) then tem=var2/var1;
retain tem;
var2=int(var1*tem);
keep var1 var2;
run;
the
【在 y**3 的大作中提到】
: help needed from sas expert!
: I have 2 variables in my sas data set-var1 var2. var2 only has value at the
: first record.i need to compute the rest of var2 based on the ratios of two
: records next to each other; for ex;
: the 2nd row ; var22=(95/87)*85; then compute var23 based on the new number
: and var12 and var13.
: how to code this in sas efficiently? thanks
: var1 var2
: 87 95
: 85
|
y**3
发帖数: 267 | 3 Thanks for the help!
But this way tem was set only var2/var1 at _n_=1. that is, tem is same for
all the rest of rows. But I need to re compute tem using the new var2 for
every rows. A do loop work?
【在 a******r 的大作中提到】
: data new;
: set old;
: if (_n_ EQ 1) then tem=var2/var1;
: retain tem;
: var2=int(var1*tem);
: keep var1 var2;
: run;
:
: the
|
a******r
发帖数: 8 | 4 According to your description, "tem=var2/var1" should have the same value
for all lines, right?
【在 y**3 的大作中提到】
: Thanks for the help!
: But this way tem was set only var2/var1 at _n_=1. that is, tem is same for
: all the rest of rows. But I need to re compute tem using the new var2 for
: every rows. A do loop work?
|
a******r
发帖数: 8 | 5 If you were not sure, try the following one.
data new;
set old;
if (_n_ EQ 1) then tem=var2/var1;
var2=var1*tem;
tem=var2/var1;
retain tem;
keep var1 var2;
run;
Be careful about the type of variables if your original types of var1 and
var2 are both integer.
【在 y**3 的大作中提到】
: Thanks for the help!
: But this way tem was set only var2/var1 at _n_=1. that is, tem is same for
: all the rest of rows. But I need to re compute tem using the new var2 for
: every rows. A do loop work?
|
y**3
发帖数: 267 | 6 Good job! thanks !!!!!!!!!!!!!
【在 a******r 的大作中提到】
: If you were not sure, try the following one.
: data new;
: set old;
: if (_n_ EQ 1) then tem=var2/var1;
: var2=var1*tem;
: tem=var2/var1;
: retain tem;
: keep var1 var2;
: run;
: Be careful about the type of variables if your original types of var1 and
|
a******c
发帖数: 291 | 7 Thanks a lot. I encountered a similar question half a year ago and used a
very clumsy method to resolve it by stacking computed rows one after another
. This is much more efficient. |
a******c
发帖数: 291 | 8 Thanks a lot. I encountered a similar question half a year ago and used a
very clumsy method to resolve it by stacking computed rows one after another
. This is much more efficient. |
