各位前辈好,我最近在做的研究涉及10个解释变量(5个百分比数据,其他都为降雨量、海拔高度等连续数据)和1个响应变量(50次测量中的超标次数)。导师让我用广义线性模型做一下,于是就在sas里面找到了genmod模块。由于是统计小白,对统计知识和sas不是太熟悉,时间很急也来不及慢慢自己学了,烦请各位前辈告知,总共11个论坛币,卑微地砸出10个求指教:
1.响应变量为超标次数,是否适合用poisson分布做?
2.在网上看的资料拼凑的程序如下,请问我想得到总体拟合程度和各个解释变量能够解释的程度及其显著性,需要对程序进行怎么改,在输出结果中分别是哪些值能够代表拟合程度(类似R方)和显著性水平?obstats、pscale分别是什么意思呢?有个type1和type3的检验,应该怎么选呢?我能从结果里面得出哪些有用的信息呢?拜谢了!
程序:DATA P162;
INFILE 'D:\sasGLM\P162.txt';
INPUT tp far set for nat art str slop wide rain alt;
RUN;
PROC GENMOD DATA=P162;
MODEL tp = far set for nat art str slop wide rain alt/ DIST = POISSON LINK = LOG obstats type1 type3;
RUN;
结果如下:
Criteria For Assessing Goodness Of Fit
Criterion DF Value Value/DF
Deviance 69 967.0024 14.0145
Scaled Deviance 69 967.0024 14.0145
Pearson Chi-Square 69 896.7709 12.9967
Scaled Pearson X2 69 896.7709 12.9967
Log Likelihood 4814.0600
Algorithm converged.
Analysis Of Parameter Estimates
Standard Wald 95% Confidence Chi-
Parameter DF Estimate Error Limits Square Pr > ChiSq
Intercept 1 -1727.68 350.9755 -2415.58 -1039.78 24.23 <.0001
far 1 1730.588 350.8332 1042.968 2418.208 24.33 <.0001
set 1 1730.781 350.8447 1043.138 2418.423 24.34 <.0001
for 1 1730.519 350.8732 1042.820 2418.218 24.32 <.0001
natwet 1 1730.502 350.8607 1042.828 2418.177 24.33 <.0001
artwet 1 1727.515 350.8053 1039.949 2415.081 24.25 <.0001
strd 1 0.7916 0.1182 0.5599 1.0233 44.84 <.0001
slo 1 -0.7782 0.1139 -1.0014 -0.5550 46.68 <.0001
pre 1 0.0003 0.0002 -0.0002 0.0007 1.40 0.2365
ele 1 0.0245 0.0122 0.0006 0.0484 4.04 0.0443
wide 1 -0.0021 0.0004 -0.0029 -0.0013 24.59 <.0001
Scale 0 1.0000 0.0000 1.0000 1.0000
LR Statistics For Type 3 Analysis
Source DF Chi- Square Pr > ChiSq
far 1 24.47 <.0001
set 1 24.48 <.0001
for 1 24.46 <.0001
natwet 1 24.47 <.0001
artwet 1 24.39 <.0001
strd 1 44.61 <.0001
slo 1 45.24 <.0001
pre 1 1.37 0.2410
ele 1 3.66 0.0558
wide 1 27.93 <.0001
万分感谢!!!