study.design = "cohort",
时间: 2024-04-15 20:03:30 浏览: 25
`study.design = "cohort"` 表示研究设计为队列研究。队列研究是一种观察性研究方法,通过追踪一组人群的特定特征或暴露因素,来观察他们在一段时间内的疾病发展情况或结果。在队列研究中,研究对象被分为两个或多个暴露组和非暴露组,然后进行长期的观察和数据收集。
在队列研究中,研究者可以根据暴露与非暴露组之间的比较,评估暴露因素与某种疾病或结果之间的关联性。这种研究设计可以提供较强的证据来支持因果关系,并且可以控制其他潜在的干扰因素。
需要注意的是,队列研究需要长期的追踪和数据收集,以便对疾病发展和结果进行准确评估。同时,对于某些疾病或结果,可能需要较大的样本量和长期的时间跟踪才能得出可靠的结论。
相关问题
我正在使用r语言绘制桑基图,下面是我的代码: ggplot(plotData, aes(x = x, stratum = stratum, alluvium = Cohort, fill = stratum, label = stratum)) + scale_x_discrete(expand = c(0, 0)) + scale_y_discrete(expand = c(0,3))+ geom_flow(width = 1/8) + #线跟方块间空隙的宽窄 geom_stratum(alpha = .9,width = 1/10) + #方块的透明度、宽度 geom_text(stat = "stratum", size = 3,color="black") + #文字大小、颜色 #不喜欢默认的配色方案,用前面自己写的配色方案 scale_fill_manual(values = c(cell_type_cols,cell_type_cols)) + xlab("") + ylab("") + theme_bw() + #去除背景色 theme(panel.grid =element_blank()) + #去除网格线 theme(panel.border = element_blank()) + #去除外层边框 theme(axis.line = element_blank(),axis.ticks = element_blank(),axis.text = element_blank()) + #去掉坐标轴 ggtitle("")+ guides(fill = FALSE) 我想设置桑基图中每个柱子中每个模块的高度限制,该怎么设置
如果你想设置每个柱子中每个模块的高度限制,可以使用`geom_text()`函数的`position`参数来调整标签的位置。具体来说,你可以使用`position_stack(vjust = 0.5)`来将标签垂直居中,或者使用`position_stack(vjust = 1)`来将标签放置在模块的顶部。以下是修改代码的示例:
```
ggplot(plotData, aes(x = x, stratum = stratum, alluvium = Cohort,
fill = stratum, label = stratum)) +
scale_x_discrete(expand = c(0, 0)) +
scale_y_discrete(expand = c(0, 3)) +
geom_flow(width = 1/8) +
geom_stratum(alpha = .9, width = 1/10) +
geom_text(stat = "stratum", size = 3, color = "black", position = position_stack(vjust = 0.5)) + # 将标签垂直居中
scale_fill_manual(values = c(cell_type_cols, cell_type_cols)) +
xlab("") + ylab("") +
theme_bw() +
theme(panel.grid = element_blank(), panel.border = element_blank(),
axis.line = element_blank(), axis.ticks = element_blank(), axis.text = element_blank()) +
ggtitle("") +
guides(fill = FALSE)
```
如果你想将标签放置在模块的顶部,可以将`vjust`参数设置为1,如下所示:
```
geom_text(stat = "stratum", size = 3, color = "black", position = position_stack(vjust = 1)) # 将标签放置在模块的顶部
```
另外,如果你想限制每个模块的高度,可以在`aes()`函数中使用`ymin`和`ymax`参数来指定每个模块的最小值和最大值。例如,你可以将`ymax`参数设置为0.5,将每个模块的高度限制为0.5个单位,如下所示:
```
ggplot(plotData, aes(x = x, stratum = stratum, alluvium = Cohort,
fill = stratum, label = stratum, ymin = 0, ymax = 0.5)) +
scale_x_discrete(expand = c(0, 0)) +
scale_y_continuous(expand = c(0, 0.5), limits = c(0, 3)) + # 将y轴的限制设置为0到3
geom_flow(width = 1/8) +
geom_stratum(alpha = .9, width = 1/10) +
geom_text(stat = "stratum", size = 3, color = "black", position = position_stack(vjust = 0.5)) +
scale_fill_manual(values = c(cell_type_cols, cell_type_cols)) +
xlab("") + ylab("") +
theme_bw() +
theme(panel.grid = element_blank(), panel.border = element_blank(),
axis.line = element_blank(), axis.ticks = element_blank(), axis.text = element_blank()) +
ggtitle("") +
guides(fill = FALSE)
```
注意,如果你使用了`ymin`和`ymax`参数来限制每个模块的高度,你需要将`scale_y_discrete()`函数改为`scale_y_continuous()`函数,并在`scale_y_continuous()`函数中设置`limits`参数。
cohort_retention=cohort_result.iloc[:,1:].divide(cohort_sizes,axis=0)
This line of code is calculating the retention rate for each cohort in a cohort analysis.
- `cohort_result` contains the number of customers who made a purchase in each month since they joined the company.
- `.iloc[:,1:]` is selecting all columns except the first one (which contains the cohort size).
- `divide` is dividing each value in the selected columns by the corresponding cohort size. This gives us the retention rate for each month since the customer joined the company, relative to the size of the cohort.
- `cohort_sizes` contains the size of each cohort (i.e. the number of customers who joined in each month).
- `axis=0` specifies that we want to divide each row by the corresponding value in `cohort_sizes`.
The resulting `cohort_retention` dataframe contains the retention rate for each cohort and each month since they joined the company.