Question

我正在创建一个python工具箱来解决基于各种输入的WiFi信号属性，对于最终结果，我希望以光栅的形式输出。我需要这个栅格根据成本栅格（距离栅格）和数字输入（频率类型以GHz和英尺 - 米转换系数）为每个单元格取一个方程值（FSPL）。下面是我尝试过的代码，但我得到一个错误：

Traceback (most recent call last):
  File "<string>", line 108, in execute
TypeError: can't multiply sequence by non-int of type 'float'.
Failed to execute (FSPL).

以下是下面的代码（第108行标记了代码本身靠近底部的写入）：

import arcpy
import math

class Toolbox(object):
    def __init__(self):
        """Define the toolbox (the name of the toolbox is the name of the
        .pyt file)."""
        self.label = "Toolbox Label Property"
        self.alias = "Toolbox Alias Property"

        # List of tool classes associated with this toolbox
        self.tools = [FSPL, WAP_Buffer]


class FSPL(object):
    def __init__(self):
        """Define the tool (tool name is the name of the class)."""
        self.label = "Free Space Path Loss"
        self.description = "This python script tool will create Free Space Path Loss to determine the dB range output from the WAPs."
        self.canRunInBackground = False

    def getParameterInfo(self):
        """Define parameter definitions"""

        param0 = arcpy.Parameter(
        displayName="Wireless Access Points",
        name="wireless_pts",
        datatype="GPFeatureLayer",
        parameterType="Required",
        direction="Input")

        param1 = arcpy.Parameter(
        displayName="Network Frequency Type",
        name="network_freq",
        datatype="String",
        parameterType="Required",
        direction="Input")
        param1.filter.type="ValueList"
        param1.filter.list = ["2.4 GHz", "5 GHz"]

        param2 = arcpy.Parameter(
        displayName="Distance Raster",
        name="dist_rast",
        datatype="GPRasterLayer",
        parameterType="Required",
        direction="Input")

        param3 = arcpy.Parameter(
        displayName="Distance Raster Units",
        name="units",
        datatype="String",
        parameterType="Required",
        direction="Input")
        param3.filter.type="ValueList"
        param3.filter.list = ["Feet", "Meters"]

        param4 = arcpy.Parameter(
        displayName="Output Raster",
        name="output_rast",
        datatype="GPRasterLayer",
        parameterType="Required",
        direction="Output")

        return [param0, param1, param2, param3, param4]

    def isLicensed(self):
        """Set whether tool is licensed to execute."""
        return True

    def updateParameters(self, parameters):
        """Modify the values and properties of parameters before internal
        validation is performed.  This method is called whenever a parameter
        has been changed."""

        return

    def updateMessages(self, parameters):
        """Modify the messages created by internal validation for each tool
        parameter.  This method is called after internal validation."""
        return

    def execute(self, parameters, messages):
        """The source code of the tool."""

        #Get inputs
        wireless_pts = parameters[0].valueAsText
        network_freq = parameters[1].valueAsText
        dist_rast = parameters[2].valueAsText
        units = parameters[3].valueAsText
        output_rast = parameters[4].valueAsText

        shapeFieldName = arcpy.Describe(wireless_pts).shapeFieldName

        #Create expression

        if network_freq == "2.4 GHz":
            hertz=2400000000
        else:
            hertz=5000000000

        if units == "Feet":
            distmod=0.3048
        else:
            distmod=1

        #equation

LINE 108 fspl= (4 * math.pi * distmod * dist_rast * hertz)/(2.99792458 * (10**8))
        output_rast = fspl



        return

我使用python相当新，可能会有一些非常基本的东西，我不会理解。这对于没有太多python经验的人来说似乎有点容易，所以我怀疑我忘记了一些大事。如果有人对如何实现我想要制作的东西有任何想法，我会很高兴听到它们。

Answer 1

我认为你的问题在于这一行：

dist_rast = parameters[2].valueAsText

如果它正在做我认为它正在返回一个string对象，该对象不能乘以浮点数（您尝试使用math.pi，可能distmod ）

相反，将其转换为浮点数并再试一次。

Python工具箱问题

1 个答案: