hours <- curriculum %>% select(-课表) %>% map_int(~ sum(!is.na(.)))怎么样去掉%>%
时间: 2024-06-21 22:01:42 浏览: 8
在R语言中,`%>%` 是管道操作符,用于将一个函数的结果传递给另一个函数,使得代码更易读。如果你想要去掉`%>%`并直接写这个操作,你可以这样改写:
```R
hours <- curriculum$课表[-is.na(curriculum$课表)] %>% map_int(sum)
```
这里,我们首先从 `curriculum` 中选择 `课表` 列,并使用 `[ ]` 来创建一个过滤后的数据框,然后用 `map_int()` 函数对过滤后的非缺失值求和。
如果你想用一行代码完成,可以省去中间变量,直接操作:
```R
hours <- sum(!is.na(curriculum$课表), na.rm = TRUE) # 假设你需要忽略NA值
```
这行代码会直接计算 `curriculum$课表` 列中非缺失值的总数。
相关问题
class <-curriculum[curriculum$课表 %in% c("1-2", "5-6"),c("周二","周五")]详细解释这句代码
这行 R 语言代码是用来从数据框(通常是一个课程表,存储了课程信息)中筛选出特定课程时间段的数据。这里有一个名为 `curriculum` 的数据框,代码执行了以下操作:
1. `curriculum$课表 %in% c("1-2", "5-6")`: 这部分使用 `%in%` 函数检查 `课表` 列中的每个元素是否存在于向量 `c("1-2", "5-6")` 中。`1-2` 和 `5-6` 可能是表示上课时间的范围,例如上午第一二节课或者下午第五六节课。
2. `curriculum[...,...]`: 使用 `[ ]` 符号来选择满足条件的行。这里筛选出的是课表在指定时间段(即包含 "1-2" 或 "5-6")并且是周二和周五的课程记录。
3. `c("周二","周五")`: 列表中的字符串 "周二" 和 "周五" 表示希望保留的上课日。
所以,整个表达式的结果是一个新的数据子集,包含了周二和周五以及上课时间段为 "1-2" 或 "5-6" 的课程。如果你想了解更多细节,可能需要查看 `curriculum` 数据框的具体结构和列名。
School-Based Curriculum Development: Is It Coming Back into Fashion? [J]. Curriculum Matters
, 2019, retrieved from https://blogs.edweek.org/edweek/curriculum/2019/08/school-based_curriculum_development.html
The article discusses the trend of school-based curriculum development, where teachers and administrators work together to create a curriculum that is tailored to the needs of their students and community. This approach allows for greater flexibility and responsiveness to changing student needs and local context, and can lead to more engaged and effective teaching and learning.
The article cites several examples of successful school-based curriculum development, including the work of the Center for Collaborative Education in Boston and the Expeditionary Learning network of schools. However, the author notes that this approach requires significant time and resources, as well as a strong commitment from school leaders and teachers.
The article also raises some potential challenges and criticisms of school-based curriculum development, such as concerns about teacher expertise and the potential for narrow or biased perspectives to influence the curriculum. The author emphasizes the importance of ongoing reflection and evaluation to ensure that school-based curriculum development remains effective and equitable.
Overall, the article suggests that school-based curriculum development may be making a comeback as educators seek more responsive and student-centered approaches to teaching and learning.
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