What is the main difference between probability density function (PDF) and histogram? A: The calculation methods for histogram and PDF are different B: The values on histogram curve are larger than the values on PDF curve C: The shapes of histogram curve and PDF curve are different D: The integration of the PDF curve equals 1, the step of ordinate axis in the histogram is 1

The difference between a histogram and a frequency polygon is: A: the frequency polygon is reported as a percent, a histogram does not report percents. B: the histogram shows frequencies while a frequency polygon shows cumulative frequencies. C: the bars in a histogram and a frequency polygon cannot be adjacent. D: open-ended classes can be accommodated with a frequency polygon.

The difference between a histogram and a frequency polygon is:

The total area of the bars in a relative frequency histogram:

使用ggplot做柱状图，应该使用哪个命令？ A: geom_bar B: geom_histogram C: geom_line D: geom_point

Histogram equalization can be used to enhance the contrast of an image.

在ggplot绘图系统中，几何映射geom与统计变换stat是成对出现

ggplot包中用于图层控制的函数是？ A: position() B: mapping() C: stat() D: geom()

histogram具有针对原始数据进行同时汇总和绘图的作用，运行下面代码： x = randn(1000,1); nbins = 25; h = histogram(x,nbins); 则在命令行窗口查看组别情况，可以输入

histogram具有针对原始数据进行同时汇总和绘图的作用，运行下面代码： x = randn(1000,1); nbins = 25; h = histogram(x,nbins); 则在命令行窗口查看分组频数情况，可以输入