GXVM class

class geosoft.gx.GXVM
In-memory vector data methods
The VM class will store vector (array) data in a memory buffer which
can be accessed using the VM methods.
The main use for the VM class is to store data in a single physical
memory location.  This memory can then be accessed by a user DLL using
the geosoft.gx.GXGEO.get_ptr_vm() function defined in gx_extern.h.
VM memory can be any size, but a VM is intended for handling relatively
small sets of data compared to a VV, which can work efficiently with
very large volumes of data.  The acceptable maximum VM size depends on
the operating system and the performance requirements of an application.
The best performance is achieved when all VM memory can be stored
comfortably within the the available system RAM.  If all VM memory
will not fit in the system RAM, the operating system virtual memory
manager will be used to swap memory to the operations systems virtual
memory paging file.  Note that the operating system virtual memory
manager is much slower than the manager used by Geosoft when working with
very large arrays in a VV.

See VV for methods to move data between a VM and a VV.
static create((GXContext)ctx, (int)arg1, (int)arg2) → GXVM:
Create a VM.
Parameters:
Returns:

VM Object
Return type:

geosoft.gx.GXVM

New in version 5.0.0.

Note:

The VM elements are initialized to dummies.
static create_ext((GXContext)ctx, (int)arg1, (int)arg2) → GXVM:
Create a VM, using one of the GS_TYPES constants special data types.
Parameters:
Returns:

VM Object
Return type:

geosoft.gx.GXVM

New in version 6.4.2.

Note:

The VM elements are initialized to dummies.
get_double((int)arg1) → float:
Get a real element from a VM.
Parameters:arg1 (int) – element wanted
Returns:Element wanted, or rDUMMY if the value is dummy or outside of the range of data.
Return type:float

New in version 5.0.0.

get_int((int)arg1) → int:
Get an integer element from a VM.
Parameters:arg1 (int) – element wanted
Returns:Element wanted, or iDUMMY if the value is dummy or outside of the range of data.
Return type:int

New in version 5.0.0.

get_string((int)arg1, (str_ref)arg2) → None:
Get a string element from a VM.
Parameters:
  • arg1 (int) – element wanted
  • arg2 (geosoft.gx.str_ref) – string in which to place element
Returns:

Nothing
Return type:

None

New in version 5.0.0.

Note:

Returns element wanted, or blank string
if the value is dummy or outside of the range of data.

Type conversions are performed if necessary.  Dummy values
are converted to "*" string.
is_null() → bool

Check if the instance of geosoft.gx.GXVM is null (undefined)

Returns:True if this is a null instance of geosoft.gx.GXVM, False otherwise.
Return type:bool`
length() → int:
Returns current VM length.
Returns:# of elements in the VM.
Return type:int

New in version 5.0.0.

static null() → GXVM

A null (undefined) instance of geosoft.gx.GXVM

Returns:A null geosoft.gx.GXVM
Return type:geosoft.gx.GXVM
re_size((int)arg1) → None:
Re-set the size of a VM.
Parameters:arg1 (int) – new size (number of elements)
Returns:Nothing
Return type:None

New in version 5.0.0.

Note:

If increasing the VM size, new elements are set to dummies.
set_double((int)arg1, (float)arg2) → None:
Set a real element in a VM.
Parameters:
  • arg1 (int) – element to set
  • arg2 (float) – value to set
Returns:

Nothing
Return type:

None

New in version 5.0.0.

Note:

Element being set cannot be < 0.

If the element is > current VM length, the VM length is
increased.  Reallocating VM lengths can lead to fragmented
memory and should be avoided if possible.
set_int((int)arg1, (int)arg2) → None:
Set an integer element in a VM.
Parameters:
  • arg1 (int) – element to set
  • arg2 (int) – value to set
Returns:

Nothing
Return type:

None

New in version 5.0.0.

Note:

Element being set cannot be < 0.

If the element is > current VM length, the VM length is
increased.  Reallocating VM lengths can lead to fragmented
memory and should be avoided if possible.
set_string((int)arg1, (str)arg2) → None:
Set a string element in a VM.
Parameters:
  • arg1 (int) – element to set
  • arg2 (str) – string to set
Returns:

Nothing
Return type:

None

New in version 5.0.0.

Note:

Element being set cannot be < 0.

If the element is > current VM length, the VM length is
increased.  Reallocating VM lengths can lead to fragmented
memory and should be avoided if possible.