portfolio

This question already has an answer here: How to convert data frame into time series? 5 answers I have a time series data of the format Time Ask Bid Trade Ask_Size Bid_Size Trade_Size 2016-11-01 09:00:12 NA 901 NA NA 100 NA 2016-11-01 09:00:21 NA NA 950 NA NA 5 2016-11-01 09:00:21 NA 950 NA NA 5 NA 2016-11-01 09:00:21 905 NA NA 10 NA NA 2016-11-01 09:00:24 NA 921 NA NA 500 NA 2016-11-01 09:00:28 NA 879 NA NA 2 NA The structure of the dataframe is str(df) 'data.frame': 35797 obs. of 7 variables: $ Time : POSIXct, format: "2016-11-01 09:00:12" "2016-11-01 09:00:21" ... $ Ask : num NA NA NA 905

I recently got very interested in portfolio optimization and started playing around in R, to create a minimum variance portfolio, library(quadprog) Dmat <- matrix(c(356.25808, 12.31581, 261.88302, 12.31581, 27.24840, 18.50515,261.88302, 18.50515,535.45960), nrow=3, ncol=3) dvec <- matrix(c(9.33, 3.33, 9.07), nrow=3, ncol=1) A.Equality <- matrix(c(1,1,1), ncol=1) Amat <- cbind(A.Equality, dvec, diag(3), -diag(3)) bvec <- c(1, 5.2, rep(0, 3), rep(-0.5, 3)) qp <- solve.QP(Dmat, dvec, Amat, bvec, meq=1) Example above has the following constraints ( example from here ) There are 4 constraints: sum

I am trying to implement Chris Coyier's example of using CSS columns to create a seamless responsive grid of images. I put Chris's files onto my server and everything looked fine. The only thing I changed was the actual images. Now, as you see on my test page , there are only 4 columns of images instead of the specified 5, using column-count:5; . The fifth column is just whitespace with no content. This only happens when the browser window is greater than 1200px. When the browser window is less than 1200px, the media queries kick in and decreases the column count 4, 3, 2, and finally 1. In