MATLAB Programming

11 Improving Performance and Memory Usage
c = rand(2.1e6,1);
The following statements can use approximately 32.4 MB of RAM. This is
because MATLAB may not be able to reuse the space previously occupied by
two 1MB arrays when allocating space for a 2.1 MB array:
a = rand(1e6,1);
b = rand(1e6,1);
clear
c = rand(2.1e6,1);
The simplest way to prevent overallocation of memory is to allocate the largest
vectors first. These statements use only about 16.4 MB of RAM:
c = rand(2.1e6,1);
clear
a = rand(1e6,1);
b = rand(1e6,1);
Working with Large Amounts of Data
If your program generates very large amounts of data, consider writing the
data to disk periodically. After saving that portion of the data, use the clear
function to remove the variable from memory and continue with the data
generation.
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