if((dx .LE. 0) .AND. (dx .NE. (X_max - X_min)) .OR.
     *(dy .LE. 0) .AND. (dy .NE. (Y_max - Y_min))) then
          write(6,*) 'Input values error:  Wrong x/y step'
          stop
      elseif(X_min .GT. X_max .OR. Y_min .GT. Y_max) then
          write(6,*) 'Input values error: Wrong min/max arguments'
          stop
      endif
      !Checking if step is too low
      !Example: x: 0.01; step: 0.000000001; - error
      temp_x = X_min + dx
      temp_y = Y_min + dy
      if(((temp_x .EQ. X_min) .AND. (dx .NE. (X_max - X_min))) 
     *.OR. ((temp_y .EQ. Y_min) .AND. (dy .NE. (Y_max - Y_min)))) then