SCTP

Prints a scatter plot of several groups of data.

Required Arguments

A —NOBS 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.

SYMBOL — CHARACTER 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.

XTITLE — CHARACTER string containing the x‑axis title. (Input)

YTITLE — CHARACTER string containing the y‑axis title. (Input)

TITLE — CHARACTER 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