SCTP
Prints a scatter plot of several groups of data.
Required Arguments
ANOBS by NVAR matrix containing the data. (Input)
ICOL — Vector of length NVAR representing the nature of each column of matrix A. (Input)
The I‑th column of A is the independent variable vector if ICOL(I) = 1. The I‑th column of A is a dependent variable vector if ICOL(I) = 2. The I‑th column of A is ignored otherwise.
RANGE — Vector of length four specifying minimum x, maximum x, minimum y and maximum y. (Input)
SCTP will calculate the range of the axis if the minimum of that range is greater than or equal to the maximum of that range.
SYMBOLCHARACTER string of length NVAR. (Input)
SYMBOL (I : I) is the character used to plot the data set represented by column I. SYMBOL(I : I) is ignored if ICOL(I 2.
XTITLECHARACTER string containing the x‑axis title. (Input)
YTITLECHARACTER string containing the y‑axis title. (Input)
TITLECHARACTER string containing the plot title. (Input)
Optional Arguments
NOBS — Number of observations. (Input)
Default: NOBS = size (A,1).
NVAR — Number of variables. (Input)
Default: NVAR = size (A,2).
LDA —Leading dimension of A exactly as specified in the dimension statement of the calling program. (Input)
Default: LDA = size (A,1).
FORTRAN 90 Interface
Generic: CALL SCTP (A, ICOL, RANGE, SYMBOL, XTITLE, YTITLE, TITLE [])
Specific: The specific interface names are S_SCTP and D_SCTP.
FORTRAN 77 Interface
Single: CALL SCTP (NOBS, NVAR, A, LDA, ICOL, RANGE, SYMBOL, XTITLE, YTITLE, TITLE)
Double: The double precision name is DSCTP.
Description
Routine SCTP prints a scatter plot of one variable on the x‑axis against several variables on the y‑axis. For multiple points, 2, 3, , 9 are used to denote the number of points at a location. The character “M” is used when the number of points is greater than 9. Any entry of the matrix A containing NaN (not a number) is ignored. See AMACH in “Machine‑Dependent Constants”.
Comments
1. Informational errors
Type
Code
Description
3
10
XTITLE is too long to fit into the page width determined by the routine PGOPT. XTITLE is truncated from the right side.
3
11
YTITLE is too long to fit into the page width determined by the routine PGOPT. YTITLE is truncated from the right side.
3
12
TITLE is too long to fit into the page width determined by the routine PGOPT. TITLE is truncated from the right side.
2. Integers 2, , 9 indicate two through nine points occupying the same plot position, respectively, and the character “M” indicates 10 or more multiple points. Consequently, it is recommended not to use any one of the above characters for SYMBOL.
3. One and only one column of A can be the independent variable vector.
4. A point is ignored if either the independent or the dependent variable contains NaN (not a number).
5. Output is written to the unit number specified by the routine UMACH (see the Reference Material section in this manual).
6. Default page width and length are 78 and 60, respectively. The user may change them by calling the routine PGOPT (see Chapter 19, “Utilities”) in advance.
Example
This example prints a scatter plot of width against length for 150 iris petals. The routine GDATA (see Chapter 19, "Utilities") is used to retrieve the Fisher iris data.
 
USE GDATA_INT
USE SCTP_INT
USE PGOPT_INT
 
IMPLICIT NONE
INTEGER ICOL(5), IDATA, IPAGE, LDA, NDA, NOBS, NVAR
REAL A(150,5), RANGE(4)
CHARACTER SYMBOL*5
!
DATA ICOL/5*0/
DATA RANGE/4*0./
DATA SYMBOL/' *'/
!
IDATA = 3
! Get Fisher Iris Data
CALL GDATA (IDATA, A, NOBS, NVAR)
! Plot petal width against
! petal length
ICOL(4) = 1
ICOL(5) = 2
! Set page width and length
IPAGE = 78
CALL PGOPT (-1, IPAGE)
IPAGE = 40
CALL PGOPT (-2, IPAGE)
 
CALL SCTP (A, ICOL, RANGE, SYMBOL, 'Petal length', &
'Petal width', 'Fisher Iris Data')
!
END
Output
 
Fisher Iris Data
:
: * **
2.4 -: * 2
: **** * * * *
: * * *
:
: **** * *
: **** * *
: *2 * *
: 32 * 2* * * *
:
: * *
P 1.6 -: * * * *
e : * 5** 2**
t : * 2 *2* *
a :
l : * 3222***
: ** * * *
w : * **
i : 2 2 * **
d :
t :
h 0.8 -:
:
: *
:
: *
: * 3** *
: 23* *
:* 24875* *
:
: * 22
0.0 -:
:...............................................................
: : : : : : :
1. 2. 3. 4. 5. 6. 7.
 
Petal length