使用Openmp的分别用1、2、3、4核计算π值，对比四核所用时间的关系，同时检测四核是否能工作(Openmp is used to calculate the relationship between 1 cores, 2, 3 and 4 cores, respectively, to compare the relationship between the four cores' time and check whether th

openmp and mpi hybrid codes

矩阵乘法的多线程并行实现，包括：simple，采用openmp对索引顺序ijk（一般写法）的循环实现并行；opt，采用openmp对索引顺序ikj（向量化友好）的循环实现并行；mkl，调用高性能数学库实现矩阵乘法。(Multi-thread parallelization of matrix-matrix multiplication: "simple" case, ijk loop (usual pattern);

wgrib2 is not simple upgrade of wgrib for grib2 files. wgrib can slice and dice grib1 files. wgrib2 is more like four drawers of kitchen utensils as well as the microwave and blender. This kitchen miracle was done by a m