Julia :HDF5数据文件读写与更新

感谢 https://github.com/JuliaLang/HDF5.jl/issues/170。其中大部分内容取自之。

如果 path 不存在，选择“w”,否则可以选择“r”.

path= "C://Users//Administrator//Desktop//test88.h5"
if isfile(path) ==false
    fid =h5open(path,"w") # isnot exist
else
    fid=h5open(path,"r") # exist
end

更精细的用法

h5open(path, "w") do file
    write(file, "A", A)  # alternatively, say "@write file A"
end

c = h5open(path, "r") do file
    read(file, "A")
end

下面以一个复合类cell来说明一下HDF5的数据文件的读写和更新。

type Cell
  origin::Array{Float64,1}     # (3 x 1 array)
  halfSize::Array{Float64,1}   # (3 x 1 array)
  nodes::Array{Float64,2}      # (8 x 3 array)
  volume::Float64
  densities::Array{Float64,1}  # (8 x 1 array)
end

一、HDF5写

nCells   = 1e6
allCells = Array(Cell, nCells) # 初始化，并分配空间
file = h5open("cellList2.hdf5", "w")
grp  = g_create(file, "CellList")
origin = d_create(grp, "origin", datatype(Float64), dataspace(3,nCells))
halfSize = d_create(grp, "halfSize", datatype(Float64), dataspace(3,nCells))
nodes = d_create(grp, "nodes", datatype(Float64), dataspace(8,3,nCells))
volume = d_create(grp, "volume", datatype(Float64), dataspace(1,nCells))
densities = d_create(grp, "densities", datatype(Float64), dataspace(8,nCells))
i = 1
for cell in cellList
  origin[:,i] = cell.origin
  halfSize[:,i] = cell.halfSize
  nodes[:,:,i] = cell.nodes
  volume[1,i] = cell.volume
  densities[:,i] = cell.densities
  if i%10000 == 0
    println(i)
  end
  i += 1
end
close(file)

二、HDF5读

  file = h5open("cellList2.hdf5", "r")
  origin = file["CellList/origin"]
  halfSize = file["CellList/halfSize"]
  nodes = file["CellList/nodes"]
  volume = file["CellList/volume"]
  densities = file["CellList/densities"]

  for i =1:nCells
    println(size(volume[:,i]))
    #cell = Cell(vec(origin[:,i]), vec(halfSize[:,i]), reshape(nodes[:,:,i],(8,3)), volume[1,i], vec(densities[:,i])) 
    cell = Cell(vec(origin[:,i]), vec(halfSize[:,i]), reshape(nodes[:,:,i], (8,3)), 0.0, vec(densities[:,i])) 
    cellList[i] = cell 
  end
  close(file)

三、HDF5数据更新

判断 文件是否存在？ isfile
先读,=>read

删除之，=>rm(path)

后再创建=>g_create