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Error using zeros Out of memory. Type HELP MEMORY for your options.

Asked by Canberk Suat Gurel on 2 Apr 2018
Latest activity Commented on by Walter Roberson
on 2 Apr 2018
I am receiving this error when I try running
Adj = zeros(x*y);
where x*y=37901, when I run
help Memory
this is what I got:
memory Memory information.
See 'doc memory' for more information on how to make the
best use of memory when running MATLAB.
memory when called without an output argument displays
information about how much memory is available and how
much is currently being used by MATLAB. All values are double
precision and in units of bytes.
USERVIEW = memory returns information about how much memory is
available and how much is currently being used by MATLAB. USERVIEW
is a structure that contains the following fields:
MaxPossibleArrayBytes -- The largest contiguous free memory block.
It is an upper bound on the largest single array that MATLAB can
currently create. This field is the smaller of these two values:
a) The largest contiguous memory block found in the
MATLAB virtual address space, or
b) The total available system memory.
To find the number of elements, divide MaxPossibleArrayBytes
by the size of each element in bytes. For example, divide by
eight for a double matrix. The actual number of elements that
that can be created is always less than this number.
MemAvailableAllArrays -- The total amount of memory available
for data. This field is the smaller of these two values:
a) The total available MATLAB virtual address space, or
b) The total available system memory.
The amount of memory available is guaranteed to be at least
as large as this field.
MemUsedMATLAB -- The total amount of system memory reserved for the
MATLAB process. This is the sum of the physical memory and
potential swap file usage.
[USERVIEW, SYSTEMVIEW] = memory returns additional, and more detailed
information about the current state of memory usage. SYSTEMVIEW is a
structure containing the following:
VirtualAddressSpace -- A 2-field structure that contains the
amount of available memory and the total amount of virtual
memory for the MATLAB process.
SystemMemory -- A 1-field structure that contains the amount of
available system memory. This number includes the amount of
available physical memory and the amount of available swap file
space on the computer running MATLAB.
PhysicalMemory -- A 2-field structure that contains the amount of
available physical memory and the total amount of physical memory
on the computer running MATLAB. It can be useful as a measure
of how much data can be accessed quickly.
The memory function is currently available on PCWIN and PCWIN64 only.
Results will vary depending on the computer running MATLAB, the load
on the computer, and what MATLAB is doing at the time.
Example 1: Run the memory command on a 32-bit Windows system:
>> memory
Maximum possible array: 677 MB (7.101e+008 bytes) *
Memory available for all arrays: 1602 MB (1.680e+009 bytes) **
Memory used by MATLAB: 327 MB (3.425e+008 bytes)
Physical Memory (RAM): 3327 MB (3.489e+009 bytes)
* Limited by contiguous virtual address space available.
** Limited by virtual address space available.
>>
Example 2: Run the memory command on a 64-bit Windows system:
>> memory
Maximum possible array: 4577 MB (4.800e+009 bytes) *
Memory available for all arrays: 4577 MB (4.800e+009 bytes) *
Memory used by MATLAB: 330 MB (3.458e+008 bytes)
Physical Memory (RAM): 3503 MB (3.674e+009 bytes)
* Limited by System Memory (physical + swap file) available.
>>
Example 3: Run the memory command with two outputs on a 32-bit Windows
system:
>> [uV sV] = memory
uV =
MaxPossibleArrayBytes: 710127616
MemAvailableAllArrays: 1.6797e+009
MemUsedMATLAB: 345354240
sV =
VirtualAddressSpace: [1x1 struct]
SystemMemory: [1x1 struct]
PhysicalMemory: [1x1 struct]
>> sV.VirtualAddressSpace
ans =
Available: 1.6797e+009
Total: 2.1474e+009
>> sV.SystemMemory
ans =
Available: 4.4288e+009
>> sV.PhysicalMemory
ans =
Available: 2.5376e+009
Total: 3.4889e+009
when I run
memory
I got the following:
>> memory
Maximum possible array: 4825 MB (5.059e+09 bytes) *
Memory available for all arrays: 4825 MB (5.059e+09 bytes) *
Memory used by MATLAB: 12369 MB (1.297e+10 bytes)
Physical Memory (RAM): 12218 MB (1.281e+10 bytes)
* Limited by System Memory (physical + swap file) available.
How can I solve this issue? (I am using MATLAB 2017b)

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1 Answer

Answer by Steven Lord
on 2 Apr 2018

Do you really want a matrix with 37901 rows and 37901 columns, which is what the command you tried to run will create? That would require a large section of contiguous memory (11491886408 bytes to be specific or approximately 11 and a half gigabytes.) If you do need to do this and you want the matrix to be sparsely populated (only a small percentage of the entries are not zero) you could try using the sparse function.
Do you want to create a vector with 37901 rows and 1 column or 1 row and 37901 columns?
zeros(x*y, 1)
zeros(1, x*y)
Do you want to create a matrix with x rows and y columns?
zeros(x, y)

  3 Comments

Yes, I need to create a 37901*37901 matrix of zeros. This is not a mistake. I found out that I didn't have enough memory (RAM) to store the variable I want to allocate. I had a few other programs running, e.g. Firefox, Chrome, PowerPoint etc. closing them up resolved the issue.
If your matrix is going to be sparsely populated, I strongly recommend you try to create or preallocate your matrix as a sparse matrix using sparse or spalloc. Doing so may save you a substantial amount of memory if your matrix has only a few nonzero elements.
If you do not have all of the information available at the time of array allocation, use spalloc. Be sure tell it how many nonzero values you expect, as each time you assign more nonzero entries than you have reserved, it needs to rebuild the sparse array.

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