<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px"><div id="yui_3_16_0_1_1441773545545_2403">Hi all,</div><div id="yui_3_16_0_1_1441773545545_2403"><br></div><div id="yui_3_16_0_1_1441773545545_2403">I want to subtract a constant value from a daily data file with 365 values. when i do this CDO, constant is subtracted from only first time step.. how can i solve this issue.</div><div id="yui_3_16_0_1_1441773545545_2403" dir="ltr">Secondly I also want to subtract one file from another, both having the same number of time steps. </div><div id="yui_3_16_0_1_1441773545545_2403" dir="ltr">Please provide any solution in GrADS or CDO.</div><div id="yui_3_16_0_1_1441773545545_2403" dir="ltr"><br></div><div id="yui_3_16_0_1_1441773545545_2403" dir="ltr">Thanks</div><div id="yui_3_16_0_1_1441773545545_2403" dir="ltr">Amina</div><div id="yui_3_16_0_1_1441773545545_2403"><br></div></div></body></html>