more accurate memory estimate

Author: scivision

+stdlib/checkRAM.m

@@ -13,20 +13,36 @@
 
 % get available RAM
 freebytes = stdlib.ram_free();
+
+% get user set preference for memory limit
+s = settings;
+ws = s.matlab.desktop.workspace;
+
+% Check if the maximum array size limit is enabled
+if ws.ArraySizeLimitEnabled.ActiveValue
+  limit_bytes = double(ws.ArraySizeLimit.ActiveValue) / 100 * stdlib.ram_total();
+else
+  limit_bytes = inf; % no limit set
+end
+
+limit_bytes = min(limit_bytes, freebytes);
+
 % variable sizing
 switch(myclass)
+  case 'complex single', bits = 64;
+  case 'complex double', bits = 128;
   case {'single','int32','uint32'}, bits = 32;
   case {'double','int64','uint64','float'}, bits = 64;
   case {'int16','uint16'}, bits = 16;
   case {'int8','uint8'}, bits = 8;
   case {'logical','bool'}, bits = 1;
-  case {'string','char'}, bits = 8; % FIXME is this correct?
+  case {'string','char'}, bits = 8;
   otherwise, error('unhandled variable class: %s', myclass)
 end
 
 newSizeBytes = prod(newSize)*bits / 8;
 
-OK = newSizeBytes < freebytes;
+OK = newSizeBytes < limit_bytes;
 
 end
 

+stdlib/ram_free.m

@@ -1,5 +1,5 @@
 %% RAM_FREE get free physical RAM
-% requires: java
+% optional: java
 %
 % get free physical RAM across operating systems
 % https://docs.oracle.com/en/java/javase/21/docs/api/jdk.management/com/sun/management/OperatingSystemMXBean.html#getFreeMemorySize()
@@ -9,12 +9,23 @@
 
 function freebytes = ram_free()
 
-b = javaOSBean();
+try
+  % memory() was added cross-platform to Octave ~ 2021.
+  % Matlab memory() at least through R2025a is still Windows only.
+  m = memory();
+  freebytes = m.MemAvailableAllArrays;
+catch e
+  switch e.identifier
+    case {'MATLAB:memory:unsupported', 'Octave:undefined-function'}
+      b = javaOSBean();
 
-if stdlib.java_api() < 14
-  freebytes = b.getFreePhysicalMemorySize();
-else
-  freebytes = b.getFreeMemorySize();
+      if stdlib.java_api() < 14
+        freebytes = b.getFreePhysicalMemorySize();
+      else
+        freebytes = b.getFreeMemorySize();
+      end
+    otherwise, rethrow(e)
+  end
 end
 
 end