Convert qLD to CSR format.

PiperOrigin-RevId: 723955038
Change-Id: I30c3dc7f59739e89ae5fff8841432bc74717ec1b

doc/APIreference/functions.rst

@@ -423,7 +423,8 @@ Get name of object with the specified mjtObj type and id, returns NULL if name n
 
 .. mujoco-include:: mj_fullM
 
-Convert sparse inertia matrix M into full (i.e. dense) matrix.
+Convert sparse inertia matrix ``M`` into full (i.e. dense) matrix.
+|br| ``dst`` must be of size ``nv x nv``, ``M`` must be of the same size as ``mjData.qM``.
 
 .. _mj_mulM:
 

doc/APIreference/functions_override.rst

@@ -233,6 +233,11 @@ found, the function will return ``distmax`` and ``fromto``, if given, will be se
    In order to determine whether a geom pair uses ``mjc_Convex``, inspect the table at the top of
    `engine_collision_driver.c <https://github.com/google-deepmind/mujoco/blob/main/src/engine/engine_collision_driver.c>`__.
 
+.. _mj_fullM:
+
+Convert sparse inertia matrix ``M`` into full (i.e. dense) matrix.
+|br| ``dst`` must be of size ``nv x nv``, ``M`` must be of the same size as ``mjData.qM``.
+
 .. _mj_mulM:
 
 This function multiplies the joint-space inertia matrix stored in mjData.qM by a vector. qM has a custom sparse format

doc/includes/references.h

@@ -272,7 +272,7 @@ struct mjData_ {
   mjtNum* qM;                // total inertia (sparse)                           (nM x 1)
 
   // computed by mj_fwdPosition/mj_factorM
-  mjtNum* qLD;               // L'*D*L factorization of M (sparse)               (nM x 1)
+  mjtNum* qLD;               // L'*D*L factorization of M (sparse)               (nC x 1)
   mjtNum* qLDiagInv;         // 1/diag(D)                                        (nv x 1)
 
   // computed by mj_collisionTree
@@ -305,7 +305,7 @@ struct mjData_ {
   mjtNum* subtree_angmom;    // angular momentum about subtree com               (nbody x 3)
 
   // computed by mj_Euler or mj_implicit
-  mjtNum* qH;                // L'*D*L factorization of modified M               (nM x 1)
+  mjtNum* qH;                // L'*D*L factorization of modified M               (nC x 1)
   mjtNum* qHDiagInv;         // 1/diag(D) of modified M                          (nv x 1)
 
   // computed by mj_resetData