Question

我的代码出现问题：当我在矩阵的第i列进行搜索时，它会出现以下错误：

if grades[:,i]!=-3:

ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

我曾尝试阅读有关此问题的较旧帖子，但无法真正解决我的问题

我正在尝试根据丹麦评分等级来编写评分函数

def computeFinalGrades(grades):
    #looping over the leth of grades
    for i in range(len(loopingrange)):
        #checking if any grade in the i-th coloumn is -3  
        if grades[:,i]==-3:
        #if a grade is equal to -3 then the output variabel gradesFinal is -3  
            gradesFinal = -3
        else:
        #looping over all grade coloumns that do not contain one or more grades of -3
            for i in range(len(loopingrange)):
              #Checking to see if any coloumn only contains 1 grade  
                if (len(grades[:,i]) == 1):
              # if a coloumn only contains 1 grade - that is also the final grade      
                    gradesFinal = grades[:,i]
               #Checking to see if coloumn contains more than 1 grade and those grades are not -3     
                elif (len(grades[:,i]) > 1):
                    #storing all the grades in a variabel - in random order
                    unsortedgrades = grades[:,i]
                    #sorting all the grades from lowest to highest
                    sortedgrades1 = np.sort(unsortedgrades)
                    #slicing the lowest grade out using indexing
                    sortedgrades = sortedgrades1[1::]
                    #finding the final grade as the mean of the n-1 grades
                    gradesFinal = np.mean(sortedgrades)
    return gradesFinal

Answer 1

grades[:,i]返回数组的第i列。这意味着它是一个数组，每行有一个元素。

您不能使用if grades[:,i]==-3:，因为grades[:,i]==-3返回一个布尔数组，不能在if语句中使用。

如果您想检查该列中的任何成绩== -3，您可以使用-3 in grades[:,i]。

Error_message：具有多个元素的数组的真值是不明确的。使用a.any（）或a.all（）

1 个答案: