#
# canola - canon canola 1614p emulator
# Copyright (C) 2011 Peter Miller
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License, version 3, as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program. If not, see <http://www.gnu.org/licenses/>.
#
; ------------------  Card-Pocket-Begin  -----------------------------------
; Title: ST-3: Correlation Coefficient
; Color: green
; Style: blank
; ------------------  Card-Pocket-End  -------------------------------------
;
; How-to-Operate:
;     [START]
;  x1 [START] y1 [START]
;  x2 [START] y2 [START]
;  x3 [START] y3 [START]
;   :    :     :    :
;  xn [START] yn [START]
;     [START] => r
;
; Example:
;      [START]
;  8.8 [START] 8.2 [START]
;  7.0 [START] 6.4 [START]
;  7.4 [START] 6.0 [START]
;      [START] => 0.92690 ; r
;
; Equations:
;  r = (n * sigma(x*y) - sigma(x)*sigma(y)) /
;      sqrt((n*sigma(x**2) - (sigma(x)**2)) *
;           (n*sigma(y) - (sigma(y)**2)))
;
    CM14        ; sigma(x)
    CM13        ; sigma(x**2)
    CM12        ; sigma(y)
    CM11        ; sigma(x*y)
    CM10        ; sigma(y**2)
    CM9         ; n
    ENT
FJ $613
    M14
    *
    +=
    M13
    RV
    *
    ENT         ; y
    M12
    SM8
    +=
    M11
    RM8
    *
    +=
    M10
    1
    M9
    RM9
    EJ $613     ; branch if they enter a new X
    RM14
    *
    +=
    /
    RM9
    -=
    M13
    RM12
    *
    +=
    /
    RM9
    -=
    M10
    RM14
    *
    RM12
    /
    RM9
    -=
    M11
    RM13
    *
    RM10
    +=
    SQRT
    /
    RM11
    RV
    ROUND 5
    +=
    PRINT       ; r