diff options
| -rw-r--r-- | README.md | 2 | ||||
| -rw-r--r-- | doc/nerv_matrix.md | 32 |
2 files changed, 33 insertions, 1 deletions
@@ -28,7 +28,7 @@ Nerv uses [luaT]\(a [Torch] library\) to define lua class in C. Enables object-oriented programming in Nerv. * __[The Nerv utility functions](doc/nerv.md)__ Inlcudes some utility functions from luaT to implement __Nerv.Class__. -* __The Nerv Matrix Package__ +* __[The Nerv Matrix Package](doc/nerv_matrix.md)__ The Matrix package is a basic package in __Nerv__ that is used to store and manipulate matrices. [luaT]:https://github.com/torch/torch7/tree/master/lib/luaT diff --git a/doc/nerv_matrix.md b/doc/nerv_matrix.md new file mode 100644 index 0000000..c710ac8 --- /dev/null +++ b/doc/nerv_matrix.md @@ -0,0 +1,32 @@ +#The Nerv Matrix Package# +Part of the [Nerv](../README.md) toolkit. + +##Description## +###Underlying structure### +In the begining is could be useful to know something about the underlying structure of a __Nerv__ matrix. +Every matrix object is a encapsulation of a C struct that describes the attributes of this matrix. +``` +typedef struct Matrix { + size_t stride; /* size of a row */ + long ncol, nrow, nmax; /* dimension of the matrix */ + union { + float *f; + double *d; + long *i; + } data; /* pointer to actual storage */ + long *data_ref; +} Matrix; +``` +It is worth mentioning that that `data_ref` is a counter which counts the number of references to its memory space, mind that it will also be increased when a row of the matrix is referenced(`col = m[2]`). A __Nerv__ matrix will deallocate its space when this counter is decreased to zero. +Also note that all assigning operation in __Nerv__ is reference copy, you can use `copy_tod` or `copy_toh` method to copy value. + +###Class hierarchy### +The class hierarchy of the matrix classes can be clearly observed in `matrix/init.c`. +First there is a abstract base class __Nerv.Matrix__, which is inherited by __Nerv.CuMatrix__ and __Nerv.MMatrix__(also abstract). +Finally, there is __Nerv.CuMatrixFloat__, __Nerv.CuMatrixDouble__, inheriting __Nerv.CuMatrix__, and __Nerv.MMatrixFloat__, __Nerv.MMatrixDouble__, inheriting __Nerv.MMatrix__. + +##Methods## +Mind that usually a matrix object can only do calculation with matrix of its own type(a __Nerv.CuMatrixFloat__ matrix can only do add operation with a __Nerv.CuMatrixFloat__). +In the methods description below, __Matrix__ could be __Nerv.CuMatrixFloat__, __Nerv.CuMatrixDouble__, __Nerv.MMatrixFloat__ or __Nerv.MMatrixDouble__. +* __Matrix = Matrix(int nrow, int ncol)__ +Returns a __Matrix__ object of `nrow` rows and `ncol` columns.
\ No newline at end of file |