y****e
发帖数: 1012 | 1 大家好~
我最近在用R，感觉无从下手。我想做一个qqplot（qunatile-quantile），输入是一个
文件（两列，第一列是measured result,第二列是理论值，都是浮点数）。输出用
qqplot画出他们的近似程度。
现在我还是不知道怎么把input feed到qqnorm, qqplot里面。有达人能给写个R 的
script吗？
我请你吃饭~~~
谢谢！ |
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Y****a
发帖数: 243 | 2 呵呵，不会用google 或 bing 的吗？
http://www.astrostatistics.psu.edu/datasets/R/html/stats/html/q
Usage section, last example:
qqplot(x, y, plot.it = TRUE, xlab = deparse(substitute(x)),
ylab = deparse(substitute(y)), ...)
如果你的问题是怎么把数据读到R里面，查看 read.csv, read.table, etc..
个人觉得比较方便的是把数据存在 .csv 格式，直接调用 read.csv
my.data <- read.csv(file="myData.csv")
qqplot(my.data,xlab="X name",ylab="Y name") |
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w*********a
发帖数: 156 | 3 想看一堆数据（70个）是否服从某个分布，用QQplot，发现上尾部好几个都在直线的上
方，并且有段距离
但是用Kolmogorov–Smirnov test 算出来的p-value又很大（>0.7),这时候能不能假定
这些数据服从这个分布呢？ |
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h***i
发帖数: 3844 | 4 sorry, Imisunderstood your question
actually, you should fix your distribution first. for example, for normal
distribution,try qqplot.
If not, then your question is invalid. |
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H***a
发帖数: 735 | 5 qqplot(Y, a+bX)? Assuming you know a, b |
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h*******1
发帖数: 9 | 6 > qqplot(u, rchi, ylab="Data Quantiles", xlab=expression(paste(chi^2, (1), "
", plain(Quantiles)))) |
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o******6
发帖数: 538 | 7 ☆─────────────────────────────────────☆
chrischang (fhcm) 于 (Mon May 12 21:59:24 2008) 提到:
Using R for Introductory Statistics
Problem 10.23
高手教教怎么做拉 作业不会做 急死了
☆─────────────────────────────────────☆
hezhi (荷芝) 于 (Mon May 12 23:59:45 2008) 提到:
response 要做transformation，完了你再看看fit的结果如何，看看qqplot，residual
plot
这种你学过regression应该没问题 |
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z****e
发帖数: 2024 | 8 what i know is a qqplot to see if the sample is from a normal distribution. |
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o****o
发帖数: 8077 | 9 如果完全没有别的信息，只有用QQplot之类的图形法先看个大概 |
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b*****n
发帖数: 685 | 10 看是不是log-normal的话，你先把data取log，再QQplot一下看看。
你的想法太简单，啥都指望一个软件搞定，这可搞不好统计啊。
么办 |
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j******1
发帖数: 62 | 11 I am trying to predict the freshmen graduate rate. I applied the
discrimimant analysis, denpendent variable is degree (graduate or not),
independent variable is hsgpa (high school gpa).
hsgpa is not normally distributed. Please see the attachment for QQplot of
hsgpa.
I applied the box-cox transformation to hsgpa to make it normal and below
is the result.
Transform | L [95% Conf. Interval] Skewness |
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S********a
发帖数: 359 | 12 我有5个datasets, 分别是a1 a5 a7 a30 a180, 想把每个文件重复做一个procedure
%macro normcheck(k) ;
proc univariate data=&k ;
var resid;
qqplot;
histogram / normal;
run;
%mend ;
%normcheck(a1);
但是这样的话，我要不停手动更换%normcheck()里的文件名，
怎么能够一次赋值就出五个procedure呢，感觉需要用do loop，怎么修改code呢？
包子答谢！！ |
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a*****3
发帖数: 601 | 13 ods html ;
%macro normcheck(namelist) /parmbuff ;
%let i = 1;
%let name_p = %scan(&namelist, &i);
%do %while ( &name_p NE );
proc univariate data = &name_p ;
var resid;
qqplot;
histogram / normal;
run;
%let i= %eval(&i+1);
%let name_p = %scan(&namelist,&i);
%end;
%mend ;
option mlogic mprint;
%normcheck(a1 a5 a7 a30 a180)
ods html close;
quit; |
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s******y
发帖数: 352 | 14 the purpose of using %nrstr is to delay the macro resolution. if there is no
%nrstr, the marco will be resolved within the datastep. the statements in
the macro will be generated and put into the statement stack. after
finishing the data step, the statement will be popped up for execution.
the statements in the stack without using %nrstr:
proc univariate data=a1 ;
var resid;
qqplot;
histogram / normal;
run;
But with the %nrstr, the % sign would be quoted and invisible to the macro
com... 阅读全帖 |
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f***a
发帖数: 329 | 15 光知道n,mean,sd这3个值，神也判断不了是不是normal吧。。。
有具体sample的话，一般就是qqplot, some normality tests, 或者不走寻常路
calculate
hellinger/kolmogorov distance between normal and empirical distribution of
your sample
by n |
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P******e
发帖数: 4 | 18 想发一张time series的qqplot图片，怎么发啊？ |
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l**********8
发帖数: 305 | 19 在实际工作中，同事确实是只plot看一眼，如果不是skewness太厉害，就算正太了。。
。而且只是看histogram 和density。 在建立linear Regression model之前，不是要
test一下 residual的normality 吗（或是看看qqplot）？ |
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