add setInfo getInfo

src/xgboost.nim

@@ -123,6 +123,62 @@ proc slice*(handle: XGDMatrix, idx: seq[int]): XGDMatrix =
     result.self.addr
   )
 
+proc setInfo*(handle: XGDMatrix, field: string, arr: seq[float32]) =
+  ## set float vector to a content in info 
+  var dummy: float32
+  check: XGDMatrixSetFloatInfo(
+    handle.self, field, 
+    if arr.len == 0: dummy.addr else: arr[0].unsafeAddr, 
+    arr.len.uint64
+  )
+
+proc setInfo*(handle: XGDMatrix, field: string, arr: seq[uint32]) =
+  ## set uint32 vector to a content in info 
+  var dummy: uint32
+  check: XGDMatrixSetUIntInfo(
+    handle.self, field, 
+    if arr.len == 0: dummy.addr else: arr[0].unsafeAddr, 
+    arr.len.uint64
+  )
+
+proc setInfo*(handle: XGDMatrix, field: string, arr: seq[string]) =
+  ## Set string encoded information of all features. 
+  var data = allocCStringArray(arr)
+  check: XGDMatrixSetStrFeatureInfo(
+    handle.self, field, 
+    data, 
+    arr.len.uint64
+  )
+
+proc saveBinary*(handle: XGDMatrix, fname: string, silent: int = 1) =
+  ## load a data matrix into binary file 
+  check: XGDMatrixSaveBinary(handle.self, fname, silent.int32)
+
+proc getFloatInfo*(handle: XGDMatrix, field: string): seq[float32] = 
+  ## get float info vector from matrix. 
+  var outLen: uint64
+  var outResult: ptr float32
+  check: XGDMatrixGetFloatInfo(handle.self, field, outLen.addr, outResult.addr)
+  result = newSeq[float32](outLen.int)
+  for i in 0 ..< outLen.int:
+    result[i] = cast[float32](cast[ByteAddress](outResult) +% i * sizeof(float32))
+
+proc getUIntInfo*(handle: XGDMatrix, field: string): seq[uint32] = 
+  ## get uint32 info vector from matrix 
+  var outLen: uint64
+  var outResult: ptr uint32
+  check: XGDMatrixGetUIntInfo(handle.self, field, outLen.addr, outResult.addr)
+  result = newSeq[uint32](outLen.int)
+  for i in 0 ..< outLen.int:
+    result[i] = cast[uint32](cast[ByteAddress](outResult) +% i * sizeof(uint32))
+
+proc getStrFeatureInfo*(handle: XGDMatrix, field: string): seq[string] =
+  ## Get string encoded information of all features. 
+  var outLen: uint64
+  var outResult: cstringArray
+  check: XGDMatrixGetStrFeatureInfo(handle.self, field, outLen.addr, outResult.addr)
+  result = cstringArrayToSeq(outResult)
+
 # -------------------------------------------------------------
 # XGBooster