diff --git a/generic_data/Functions/functions.xml b/generic_data/Functions/functions.xml
index d6dfa26..7f96880 100644
--- a/generic_data/Functions/functions.xml
+++ b/generic_data/Functions/functions.xml
@@ -77,6 +77,13 @@
         <info_brief>Spearman coefficient of two parameters</info_brief>
         <new_kernel>#spearman</new_kernel>
     </function>
+    <function name="spectrum_(,)" args="1" kind="time" group="stat">
+        <prompts>
+                <prompt>input window time in secs</prompt>
+        </prompts>
+        <info_brief>Fourier spectrum  function</info_brief>
+        <new_kernel>#spectrum</new_kernel>
+    </function>
     <function name="mean_sm_(,)" args="1" kind="sliding" group="stat">
 	<prompts>
         	<prompt>input averaging time in secs</prompt>
--
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