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Lapis Lazuli | Level 10

## Dynamically Calculate of Variables

Hello,

I have tuition fees laid out for 4 years (Variables `Fee_YR_01-Fee_YR_04`) starting current year (`Fee_YR_01`). Variables `Increase_YR_01-Increase_YR_04` in the sample dataset shows the proposed tuition fee increase rate (in percent) based on the previous year. I want to calculate the future tuition based on this proposed tuition increase rate (in the new variables Fee_New_YR_02 - Fee_New_YR_04). I want a dynamic solution for this calculation.  Thank you all.

My data set looks like this:

``````data have;
input Fee_YR_01 Fee_YR_02 Fee_YR_03 Fee_YR_04 Increase_YR_01 Increase_YR_02 Increase_YR_03 Increase_YR_04;
datalines;
1000	1050	1100	1150	0	20	20	20
1000	1070	1100	1150	0	20	20	20
3000	3100	3150	3200	0	15	15	15
3000	3200	3200	3300	0	15	15	15
4000	4150	4200	4250	0	15	15	15
4000	4200	4300	4350	0	15	15	15

;
RUN;``````

This is the output I want:

 Fee_New_YR_02 Fee_New_YR_03 Fee_New_YR_04 1200 1260 1320 1200 1284 1320 3450 3565 3622.5 3450 3680 3680 4600 4772.5 4830 4600 4830 4945

Calculations: Fee_New_YR_02=Fee_YR_01 * 1.2 (increased by 20%)

I have shown you a small set of data. But I have 150 variables for tuition fees and 150 variables for the tuition rate increase.  So I need help on how to do it dynamically.

1 ACCEPTED SOLUTION

Accepted Solutions
PROC Star

## Re: Copy first observation till the end

Look up the RETAIN statement, which tells SAS to avoid resetting new variables to missing values from iteration to iteration.  You apparently want to retain the values of the Fee_New_AY_01 - Fee_New_AY_04 variables calculated when _n_=1.

--------------------------
The hash OUTPUT method will overwrite a SAS data set, but not append. That can be costly. Consider voting for Add a HASH object method which would append a hash object to an existing SAS data set

Would enabling PROC SORT to simultaneously output multiple datasets be useful? Then vote for
Allow PROC SORT to output multiple datasets

--------------------------
8 REPLIES 8
Lapis Lazuli | Level 10

## Dynamic Calculations of Variables

Hello,

I have tuition fees laid out for 4 years (Variables `Fee_YR_01-Fee_YR_04`) starting current year (`Fee_YR_01`). Variables `Increase_YR_01-Increase_YR_04` in the sample dataset shows the proposed tuition fee increase rate (in percent) based on the previous year. I want to calculate the future tuition based on this proposed tuition increase rate (in the new variables Fee_New_YR_02 - Fee_New_YR_04). I want a dynamic solution for this calculation.  Thank you all.

My data set looks like this:

``````data have;
input Fee_YR_01 Fee_YR_02 Fee_YR_03 Fee_YR_04 Increase_YR_01 Increase_YR_02 Increase_YR_03 Increase_YR_04;
datalines;
1000	1050	1100	1150	0	20	20	20
1000	1070	1100	1150	0	20	20	20
3000	3100	3150	3200	0	15	15	15
3000	3200	3200	3300	0	15	15	15
4000	4150	4200	4250	0	15	15	15
4000	4200	4300	4350	0	15	15	15

;
RUN;``````

This is the output I want:

 Fee_New_YR_02 Fee_New_YR_03 Fee_New_YR_04 1200 1260 1320 1200 1284 1320 3450 3565 3622.5 3450 3680 3680 4600 4772.5 4830 4600 4830 4945

Calculations: Fee_New_YR_02=Fee_YR_01 * 1.2 (increased by 20%)

I have shown you a small set of data. But I have 150 variables for tuition fees and 150 variables for the tuition rate increase.  So I need help on how to do it dynamically.

Super User

## Re: Dynamically Calculate of Variables

Please do not post the question in multiple locations.

Update your dimensions and variable series accordingly and this should work:

``````
data want;
set have;

array fee_hist (4) fee_yr_01 - fee_yr_04;
array increase(4) increase_yr_01 - increase_yr_04;
array fee_new (2:4) fee_new_yr_02 - fee_new_yr_04;

do i=2 to 4;
fee_new(i) = fee_hist(i-1) * (1+(increase(i)/100));
end;

run;
``````

Or slightly more dynamically, update your end of the series:

``````data want;
set have;

array fee_hist (*) fee_yr_01 - fee_yr_04;
array increase(*) increase_yr_01 - increase_yr_04;
array fee_new (*) fee_new_yr_02 - fee_new_yr_04;

do i=2 to dim(fee_hist);
fee_new(i-1) = fee_hist(i-1) * (1+(increase(i)/100));
end;

run;``````

Here's a tutorial on using Arrays in SAS
https://stats.idre.ucla.edu/sas/seminars/sas-arrays/

@mlogan wrote:

Hello,

I have tuition fees laid out for 4 years (Variables `Fee_YR_01-Fee_YR_04`) starting current year (`Fee_YR_01`). Variables `Increase_YR_01-Increase_YR_04` in the sample dataset shows the proposed tuition fee increase rate (in percent) based on the previous year. I want to calculate the future tuition based on this proposed tuition increase rate (in the new variables Fee_New_YR_02 - Fee_New_YR_04). I want a dynamic solution for this calculation.  Thank you all.

My data set looks like this:

``````data have;
input Fee_YR_01 Fee_YR_02 Fee_YR_03 Fee_YR_04 Increase_YR_01 Increase_YR_02 Increase_YR_03 Increase_YR_04;
datalines;
1000	1050	1100	1150	0	20	20	20
1000	1070	1100	1150	0	20	20	20
3000	3100	3150	3200	0	15	15	15
3000	3200	3200	3300	0	15	15	15
4000	4150	4200	4250	0	15	15	15
4000	4200	4300	4350	0	15	15	15

;
RUN;``````

This is the output I want:

 Fee_New_YR_02 Fee_New_YR_03 Fee_New_YR_04 1200 1260 1320 1200 1284 1320 3450 3565 3622.5 3450 3680 3680 4600 4772.5 4830 4600 4830 4945

Calculations: Fee_New_YR_02=Fee_YR_01 * 1.2 (increased by 20%)

I have shown you a small set of data. But I have 150 variables for tuition fees and 150 variables for the tuition rate increase.  So I need help on how to do it dynamically.

Lapis Lazuli | Level 10

## Re: Dynamically Calculate of Variables

Thank you Reeza. Your code worked for me. I just have slightly different requirements now and wondering if you can help.

I want the calculated output of the first row will be copied below all the way to the end.

I was able to do the calculation on the first line, but don't know how to copy downward. Thank you for your help.

``````data have;
input Fee_YR_01 Fee_YR_02 Fee_YR_03 Fee_YR_04 Increase_YR_01 Increase_YR_02 Increase_YR_03 Increase_YR_04;
datalines;
1000	1050	1100	1150	0	20	20	20
1000	1070	1100	1150	0	20	20	20
3000	3100	3150	3200	0	15	15	15
3000	3200	3200	3300	0	15	15	15
;
RUN;

DATA Want;
SET  Have;

ARRAY Increase_Rate(*) Increase_YR_01 - Increase_YR_04;
ARRAY Fee_New(*)        Fee_New_AY_01 - Fee_New_AY_04;

Fee_New_AY_01=Fee_YR_01;
DO i=2 TO dim(Fee_New);

IF _n_=1 THEN fee_new(i) = FLOOR(( fee_new(i-1) * (1+(Increase_Rate(i)/100)) )/10)*10;

END;
DROP i;
RUN;``````

Expected Output:

 Fee_YR_01 Fee_YR_02 Fee_YR_03 Fee_YR_04 Increase_YR_01 Increase_YR_02 Increase_YR_03 Increase_YR_04 Fee_New_AY_01 Fee_New_AY_02 Fee_New_AY_03 Fee_New_AY_04 1000 1050 1100 1150 0 20 20 20 1000 1200 1440 1720 1000 1070 1100 1150 0 20 20 20 1000 1200 1440 1720 3000 3100 3150 3200 0 15 15 15 3000 1200 1440 1720 3000 3200 3200 3300 0 15 15 15 3000 1200 1440 1720

Lapis Lazuli | Level 10

## Copy first observation till the end

Hi all,

I have lat 4 year tuition fee laid out as Fee_YR_01-Fee_YR_04 and their corresponding increased rate Increase_YR_01-Increase_YR_04. I want 4 new rows which will calculate the tuition fee for the next 4 years based on their previous year tuitions and corresponding increase. But instead of calculating all 4 rows, I want the calculated output of the first row to be copied below all the way to the end.

I was able to do the calculation on the first row, but don't know how to copy downward. Can anyone help please. Thank you

``````data have;
input Fee_YR_01 Fee_YR_02 Fee_YR_03 Fee_YR_04 Increase_YR_01 Increase_YR_02 Increase_YR_03 Increase_YR_04;
datalines;
1000	1050	1100	1150	0	20	20	20
1000	1070	1100	1150	0	20	20	20
3000	3100	3150	3200	0	15	15	15
3000	3200	3200	3300	0	15	15	15
;
RUN;

DATA Want;
SET  Have;

ARRAY Increase_Rate(*) Increase_YR_01 - Increase_YR_04;
ARRAY Fee_New(*)        Fee_New_AY_01 - Fee_New_AY_04;

Fee_New_AY_01=Fee_YR_01;
DO i=2 TO dim(Fee_New);

IF _n_=1 THEN fee_new(i) = FLOOR(( fee_new(i-1) * (1+(Increase_Rate(i)/100)) )/10)*10;

END;
DROP i;
RUN;``````

Expected Output:

 Fee_YR_01 Fee_YR_02 Fee_YR_03 Fee_YR_04 Increase_YR_01 Increase_YR_02 Increase_YR_03 Increase_YR_04 Fee_New_AY_01 Fee_New_AY_02 Fee_New_AY_03 Fee_New_AY_04 1000 1050 1100 1150 0 20 20 20 1000 1200 1440 1720 1000 1070 1100 1150 0 20 20 20 1000 1200 1440 1720 3000 3100 3150 3200 0 15 15 15 3000 1200 1440 1720 3000 3200 3200 3300 0 15 15 15 3000 1200 1440 1720

PROC Star

## Re: Copy first observation till the end

Look up the RETAIN statement, which tells SAS to avoid resetting new variables to missing values from iteration to iteration.  You apparently want to retain the values of the Fee_New_AY_01 - Fee_New_AY_04 variables calculated when _n_=1.

--------------------------
The hash OUTPUT method will overwrite a SAS data set, but not append. That can be costly. Consider voting for Add a HASH object method which would append a hash object to an existing SAS data set

Would enabling PROC SORT to simultaneously output multiple datasets be useful? Then vote for
Allow PROC SORT to output multiple datasets

--------------------------
Lapis Lazuli | Level 10

## Re: Copy first observation till the end

Thank you mkeintz. It worked for me perfectly. Never used this RETAIN function before. Today I have learded something new.
Lapis Lazuli | Level 10

## Re: Copy first observation till the end

Hi mkeintz, Do you know how I can stop RETAIN function to copy the value all the way till the blank line? I want it to stop at one point when my another by value (sorted column) ends.

Thanks.

Jade | Level 19

## Re: Copy first observation till the end

I have merged your posts, please don't repost questions.

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