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Hi All,<br>
<br>
I am trying to plot confidence interval on a regression line (like
attached image)<br>
<br>
I have x and y two variables.<br>
<br>
x varies between -0.07 and 0.06<br>
y varies between -0.8 and 0.5 <br>
<br>
I followed following steps: <br>
<br>
step 1: rc = regline (x,y)<br>
<br>
step 2: yReg = rc*x + rc@yintercept ; regression line<br>
<br>
step 3:
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<i> a = rc@rstd</i> * 2.048 ; where
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<i>t</i> for 0.975 and 28 degrees of freedom
is 2.048 [table look-up].<br>
<br>
step 4: confidence interval rc1 = rc+a and rc2 = rc-a<br>
<br>
step 5: confidence interval around regression line <br>
yReg_1 = rc1*x + rc@yintercept<br>
yReg_2 = rc2*x + rc@yintercept<br>
<br>
But I am not getting the expected plot. Moreover yReg_1 and yReg_2
intersect each other.<br>
Could you please point out what I am doing wrong.<br>
<br>
with regards<br>
-Debasish<br>
<br>
<br>
<br>
<br>
<br>
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