Module oc_cd_mod

1.

Purpose: conjugate-directions descent step

		      CD($\bold m,\bold R,\bold g,\bold G$)  {
		 		 $\b_i =-\frac{\left (\G^*\cdot\S\right )}{\left (\S^*\cdot\S\right )}$ $\left \{\begin{array}
{l} \bold s=\bold g+\sum\limits_1^{k-1}\b_i\bold s_i \\  \S=\bold G+\sum\limits_1^{k-1}\b_i\S_i\end{array}\right .$
		 		 $\alpha= -\frac{\left (\S^*\cdot\R\right ) }{\left (\S^*\cdot\S\right )}$ 		$\left \{\begin{array}
{l} \bold m=\bold m+\alpha\bold s\\  \bold R=\bold R+\alpha\S \end{array}\right .$ 
		 		 }

2.

Functions and subroutines

(a)

integer function oc_cd(forget,x_,g_,rr_,gg_,s_,ss_,maxmem)

• forget: re-initialize operator
• x_: model file tag
• >_: gradient file tag
• rr_: residual file tag
• >g_: conjugate gradient file tag
• s_: previous step file tag
• ss_: conjugate previous step file tag