自己写了一个线性加平台的程序，如下：
DATA  A ;
INFILE  'd:\book2.prn';
INPUT  aa  ry;
TITLE1  'Yield  Response Date';
TITLE2  'LRP Model';
PROC  NLIN DATA=A BEST=3;
PARMS A=6000 to 9200 by 200 B=-30 to 30 by 2 k=0 to 400 by 20;
IF AA<k THEN DO;
MODEL RY = A +B*AA;
DER.A =1;
DER.B=AA;
DER.K=0;
END;
ELSE DO;
MODEL RY = A + B*K;
DER.A =1;
DER.B=K;
DER.K=B;
END;
FILE PRINT;
IF _OBS_ = 1 AND _MODEL_= 0 THEN DO;
PLATEAU = A+B*K;
PUT PLATEAU=;
END;
PLATEAU = A + B*K;
ID PLATEAU;
OUTPUT
OUT=NEW P=PRY PARMS=A B K SSE=SSE;
RUN;
PROC
PLOT;
PLOT RY*AA='+' PRY*AA='*'/OVERLAY;
RUN;
结果输出仅有平台产量，没有截距，斜率、R方等其他数值。请高手指教