search for: hydrographic

Dear R community, I'm hoping someone out there has perhaps done this and can share their code and/or expertise with me. I need to pull recession periods out of a hydrograph - can anyone help me with this? I want to create a subset from streamflow data that consists of just the recession curves - the decreasing runoff after the passage of a peak flow. would really appreciate any help on

The small bit of script below is an example of what I'm attempting to do - find the day on which the 'center of mass' occurs. In case that is the wrong term, I'd like to know the day that essentially cuts the area under the curve in to two equal parts: set.seed(4004) Date <- seq(as.Date('2000-09-01'), as.Date('2000-09-30'), by='day') hyd <-

The University of Miami's Rosenstiel School of Marine and Atmospheric Sciences (RSMAS) is seeking a research associate to work with hydrographic data. The objective of the project is to develop statistical models for estimating salinity and density from observations of temperature together with knowledge of location and time. Because the relationship between salinity and temperature can be highly variable due to meandering fronts, it is i...

...C password, Unix password, and Samba password, (by hand), then I can browse to the user files on the Samba machine without being challenged for password. Sounds great. But I can't seem to get smbpasswd to allow the ordinary user to change their Samba password. Any suggestions? Michael Ruxton Hydrographic Systems Analyst (902) 426-4227 fax: (902) 426-1893 Canadian Hydrographic Service (Atlantic) 1 Challenger Drive PO Box 1006 Bedford Institute of Oceanography Dartmouth, NS B2Y 4A2 Once we assuage our conscience by calling something a "necessary evil," it begins to look more and more nece...

The University of Miami's Rosenstiel School of Marine and Atmospheric Sciences (RSMAS) is seeking a research associate to work with hydrographic data. The objective of the project is to develop statistical models for estimating salinity and density from observations of temperature together with knowledge of location and time. Because the relationship between salinity and temperature can be highly variable due to meandering fronts, it is i...

Hi Eric, How about match( TRUE, cumsum(hyd/sum(hyd)) > .5 ) - 1 HTH, Eric On Sat, Dec 16, 2017 at 3:18 PM, Morway, Eric <emorway at usgs.gov> wrote: > The small bit of script below is an example of what I'm attempting to do - > find the day on which the 'center of mass' occurs. In case that is the > wrong term, I'd like to know the day that essentially cuts

Eric B's response provided just the kind of quick & simple solution I was hoping for (appears as the function com below). However, I once again failed to take advantage of the power of R and have reverted back to using a for loop for the next step of the processing. The example below (which requires the library EGRET for pulling an example dataset) works, but probably can be replaced

Hi Eric, the following works for me. HTH, Eric library(EGRET) StartDate <- "1990-10-01" EndDate <- "2017-09-30" siteNumber <- "10310000" QParameterCd <- "00060" Daily <- readNWISDaily(siteNumber, QParameterCd, StartDate, EndDate) # Define 'center of mass' function com <- function(x) { match(TRUE, cumsum(x/sum(x)) > 0.5) -