I am using the termstrc package to fit ns curve. Below is the code. I am working on removing bonds to see if I get a good starting value. In the mean time any help is appreciated to understand vmmin error. Out of 2,133 observations I get this error 250 times - so overall pretty good performance of the package given the query does not really restrict price ranges.
My guess is that the bonds that I am using are causing the problem. Thus, I am systematically removing bonds to find the culprit. There are a couple of seasoned 30-year bonds with some big handles over 140 as well as plently of short bonds but my guess is the long bonds.
I realize that when curve fitting I may need to restrict prices but before I do that I would like to understand vmmin