Proc Luaを用いたオブジェクト指向プログラミング

目的

  1. データセットの情報を簡便に取得するために作成．

メソッドの定義

  1. datasetclass.new(_ds)：コンストラクタの作成
  2. datasetclass.nobs：レコードの数
  3. datasetclass.nvars：変数の数
  4. datasetclass.meta：データセットのメタ情報

Sample Program (Library作成)

In [5]:
proc lua;
  submit;
    -- prototype
    datasetclass={}
    datasetclass.nobs = function(self)
      local dsid = sas.open(self.ds)
      local nobs = sas.nobs(dsid)
      sas.close(dsid)
      return nobs
    end
    
    datasetclass.nvars = function(self)
      local dsid = sas.open(self.ds)
      local nvars = sas.nvars(dsid)
      sas.close(dsid)
      return nvars
    end

    datasetclass.meta = function(self)
      local i = 1
      local meta={}
      local dsid = sas.open(self.ds)
      for i = 1, sas.nvars(dsid) do
        meta[i]=table.tostring(sas.varinfo(dsid,i))
      end
      sas.close(dsid)
      return meta
    end
    
    -- new method (constructor)
    datasetclass.new = function(_ds)
      local obj = {}
      obj.ds = _ds
      setmetatable(obj,{__index=datasetclass})
      return obj
    end
    
  endsubmit;
run;
Out[5]:

155  ods listing close;ods html5 file=stdout options(bitmap_mode='inline') device=png; ods graphics on / outputfmt=png;
NOTE: Writing HTML5 Body file: STDOUT
156  
157  proc lua;
158    submit
158!         ;
159      -- prototype
160      datasetclass={}
161      datasetclass.nobs = function(self)
162        local dsid = sas.open(self.ds)
163        local nobs = sas.nobs(dsid)
164        sas.close(dsid)
165        return nobs
166      end
167  
168      datasetclass.nvars = function(self)
169        local dsid = sas.open(self.ds)
170        local nvars = sas.nvars(dsid)
171        sas.close(dsid)
172        return nvars
173      end
174  
175      datasetclass.meta = function(self)
176        local i = 1
177        local meta={}
178        local dsid = sas.open(self.ds)
179        for i = 1, sas.nvars(dsid) do
180          meta[i]=table.tostring(sas.varinfo(dsid,i))
181        end
182        sas.close(dsid)
183        return meta
184      end
185  
186      -- new method (constructor)
187      datasetclass.new = function(_ds)
188        local obj = {}
189        obj.ds = _ds
190        setmetatable(obj,{__index=datasetclass})
191        return obj
192      end
193  
194    endsubmit;
195  run;
NOTE: Resuming Lua state from previous PROC LUA invocation.
NOTE: PROCEDURE LUA used (Total process time):
      real time           0.00 seconds
      cpu time            0.01 seconds
      
196  ods html5 close;ods listing;

197

Sample Program (テスト実行)

In [4]:
proc lua;
  submit;
  
    -- main(1)
    local sampleds1=datasetclass.new("sashelp.class")
    print("nobs=",sampleds1:nobs())
    print("nvars=",sampleds1:nvars())
    for key, val in pairs(sampleds1:meta()) do
      print(key, val)
    end
    
    -- main(2)
    local sampleds2=datasetclass.new("sashelp.air")
    print("nobs=",sampleds2:nobs())
    print("nvars=",sampleds2:nvars())
    for key, val in pairs(sampleds2:meta()) do
      print(key, val)
    end
    
  endsubmit;
run;
Out[4]:

129  ods listing close;ods html5 file=stdout options(bitmap_mode='inline') device=png; ods graphics on / outputfmt=png;
NOTE: Writing HTML5 Body file: STDOUT
130  
131  proc lua;
132    submit
132!         ;
133  
134      -- main(1)
135      local sampleds1=datasetclass.new("sashelp.class")
136      print("nobs=",sampleds1:nobs())
137      print("nvars=",sampleds1:nvars())
138      for key, val in pairs(sampleds1:meta()) do
139        print(key, val)
140      end
141  
142      -- main(2)
143      local sampleds2=datasetclass.new("sashelp.air")
144      print("nobs=",sampleds2:nobs())
145      print("nvars=",sampleds2:nvars())
146      for key, val in pairs(sampleds2:meta()) do
147        print(key, val)
148      end
149  
150    endsubmit;
151  run;
NOTE: Resuming Lua state from previous PROC LUA invocation.
nobs=    19
nvars=    5
1    table: 00007F7DAD700320=
{
  ["fmt_dec"]=0
  ["type"]="C"
  ["label"]=""
  ["fmt_width"]=0
  ["informat"]=""
  ["name"]="Name"
  ["infmt_dec"]=0
  ["format"]=""
  ["infmt_width"]=0
  ["length"]=8
}
2    table: 00007F7DAD718840=
{
  ["fmt_dec"]=0
  ["type"]="C"
  ["label"]=""
  ["fmt_width"]=0
  ["informat"]=""
  ["name"]="Sex"
  ["infmt_dec"]=0
  ["format"]=""
  ["infmt_width"]=0
  ["length"]=1
}
3    table: 00007F7DAD70BB20=
{
  ["fmt_dec"]=0
  ["type"]="N"
  ["label"]=""
  ["fmt_width"]=0
  ["informat"]=""
  ["name"]="Age"
  ["infmt_dec"]=0
  ["format"]=""
  ["infmt_width"]=0
  ["length"]=8
}
4    table: 00007F7DAD71D7A0=
{
  ["fmt_dec"]=0
  ["type"]="N"
  ["label"]=""
  ["fmt_width"]=0
  ["informat"]=""
  ["name"]="Height"
  ["infmt_dec"]=0
  ["format"]=""
  ["infmt_width"]=0
  ["length"]=8
}
5    table: 00007F7DAD70A900=
{
  ["fmt_dec"]=0
  ["type"]="N"
  ["label"]=""
  ["fmt_width"]=0
  ["informat"]=""
  ["name"]="Weight"
  ["infmt_dec"]=0
  ["format"]=""
  ["infmt_width"]=0
  ["length"]=8
}
nobs=    144
nvars=    2
1    table: 00007F7DAD715500=
{
  ["fmt_dec"]=0
  ["type"]="N"
  ["label"]=""
  ["fmt_width"]=0
  ["informat"]=""
  ["name"]="DATE"
  ["infmt_dec"]=0
  ["format"]="MONYY"
  ["infmt_width"]=0
  ["length"]=8
}
2    table: 00007F7DAD71B860=
{
  ["fmt_dec"]=0
  ["type"]="N"
  ["label"]="international airline travel (thousands)"
  ["fmt_width"]=0
  ["informat"]=""
  ["name"]="AIR"
  ["infmt_dec"]=0
  ["format"]=""
  ["infmt_width"]=0
  ["length"]=8
}
NOTE: PROCEDURE LUA used (Total process time):
      real time           0.00 seconds
      cpu time            0.00 seconds
      
152  ods html5 close;ods listing;

153