func InsertString(ih *iup.Ihandle, index, sample_index int, x string, y float64) {
cX := C.CString(x)
defer C.free(unsafe.Pointer(cX))
C.IupPPlotInsertStr(ih.C(), C.int(index), C.int(sample_index), cX, C.float(y))
}
func (h *IupPPlot) InsertStr(index, sample_index int, x string, y float32) {
cx := iup.NewCS(x)
iup.FreeCS(cx)
C.IupPPlotInsertStr(toNative(h), C.int(index), C.int(sample_index), (*C.char)(cx), C.float(y))
}