search for: hydrologist

...s) {} However, I'm not finding a clue on how to accomplish this, if it can be done. Would someone with more R experience lend a helping hand please? A reference (so I can continue learning) would also be appreciated. Thanks... -=d David Thompson, Ph.D., P.E., D.WRE, CFM Civil Engineer/Hydrologist

...3021078457153,-1,-1,-1,1.82633400562222,1.60831204269733,-1,2.45313479655685,-1,-1,-1,-1,-1,-1,-1,-1) fit1 <- rq(y ~ x, tau = .5) Any feedback would be greatly appreciated. Thanks Steve -- =============================================== Steven R. Corsi Phone: (608) 821-3835 Research Hydrologist email: srcorsi at usgs.gov U.S. Geological Survey Wisconsin Water Science Center 8505 Research Way Middleton, WI 53562

Good morning and I appreciate the availability of a help-list. I am a professional hydrologist, but not a professional statistician. Yet I find myself using statistical tools at least part of the time. My discovery of the R-project through a friend has been most helpful. Here is my problem: I'm tasked with fitting a dataset comprising correlated discharges from adjacent watershed...

...l.m*b2)/(theta*(0.16-b)))))), data = df, start=list (a=1, b=0.5), trace=TRUE) ----- I am likely "over parameterizing", but I must admit, that I am not entirely sure what that means. Any help offered would be greatly appreciated. I am sorry if I sound naive, but I am an ecologist, not a hydrologist. Kate [[alternative HTML version deleted]]

...rs <- unique(Daily$waterYear) for(i in (1:length(wyrs))){ OneYr <- Daily[Daily$waterYear==wyrs[i], ] mid <- com(OneYr$Q) if(i==1){ midPts <- as.Date(OneYr$Date[mid]) } else { midPts <- c(midPts, as.Date(OneYr$Date[mid])) } } Eric Morway Research Hydrologist Nevada Water Science Center U.S. Geological Survey 2730 N. Deer Run Rd. Carson City, NV 89701 (775) 887-7668 *orcid*: 0000-0002-8553-6140 <http://orcid.org/0000-0002-8553-6140> On Sat, Dec 16, 2017 at 5:32 AM, Eric Berger <ericjberger at gmail.com> wrote: > Hi Eric, > How abo...

...gt; OneYr <- Daily[Daily$waterYear==wyrs[i], ] > mid <- com(OneYr$Q) > if(i==1){ > midPts <- as.Date(OneYr$Date[mid]) > } else { > midPts <- c(midPts, as.Date(OneYr$Date[mid])) > } > } > > > > Eric Morway > Research Hydrologist > Nevada Water Science Center > U.S. Geological Survey > 2730 N. Deer Run Rd. > <https://maps.google.com/?q=2730+N.+Deer+Run+Rd.Carson+City,+NV+89701+(775&entry=gmail&source=g> > Carson City, NV 89701 > <https://maps.google.com/?q=2730+N.+Deer+Run+Rd.Carson+City,+...

...ent, analysis, interpolation and plot of hydrological time series, mainly oriented to hydrological modelling tasks. So far, it only works with daily / monthly / seasonal / annual time series. The focus of this package has been put in providing a collection of functions useful for the daily work of hydrologists, and although an effort was made to optimise each function as much as possible, functionality has had priority over speed. ############ # hydroGOF # ############ 2) hydroGOF is a package for comparison of simulated and observed hydrological time series: http://cran.r-project.org/web/packages/h...

...ent, analysis, interpolation and plot of hydrological time series, mainly oriented to hydrological modelling tasks. So far, it only works with daily / monthly / seasonal / annual time series. The focus of this package has been put in providing a collection of functions useful for the daily work of hydrologists, and although an effort was made to optimise each function as much as possible, functionality has had priority over speed. ############ # hydroGOF # ############ 2) hydroGOF is a package for comparison of simulated and observed hydrological time series: http://cran.r-project.org/web/packages/h...

...have used the following code to calculate monthly evaporation but what I need is daily evapotranspiration. Epot <- thornthwaite(Tave, lat, na.rm = FALSE) # Evaluates evapotranspiration for each month. Do you have any code which works for daily timestep ? Its more technical question, may be some hydrologist has gone across it already. Thanks in advance !Anup KhanalNTNU ..................Anup KhanalNorwegian Institute of science and Technology (NTNU)Trondheim, NorwayMob:(+47) 45174313 [[alternative HTML version deleted]]

...t;watermarking" effect is not happening in my script, but does work as expected, manually, at the R prompt. I'm sure this is a graphics device related issue, but I have not been able to find a solution through my searches. Thank you, Tom -- Thomas E Adams Development & Operations Hydrologist National Weather Service Ohio River Forecast Center 1901 South State Route 134 Wilmington, OH 45177 http://www.erh.noaa.gov/er/ohrfc/ EMAIL: thomas.adams@noaa.gov VOICE: 937-383-0528 FAX: 937-383-0033 [[alternative HTML version deleted]]

...z data from Z to the bottom to find the storage. Plot the storage at each water surface to get an idea of the shape and then use lm(Elevation~f(Storage) where f(Storage) may be a cubic or quartic polynomial. Then double the Storage and calculate Elevation. This type of thing is done everyday by hydrologists. Good luck David K Stevens, PhD, PE, Professor Civil and Environmental Engineering Utah Water Research Laboratory Utah State University 8200 Old Main Hill Logan, UT 84322-8200 david.stevens at usu.edu (435) 797-3229 (office) On 4/9/2024 8:01 AM, peter dalgaard wrote: > So, you know how to ge...

...the bottom to find the storage. Plot the storage at > each water surface to get an idea of the shape and then use > lm(Elevation~f(Storage) where f(Storage) may be a cubic or quartic > polynomial. Then double the Storage and calculate Elevation. This type > of thing is done everyday by hydrologists. > > Good luck > > David K Stevens, PhD, PE, Professor > Civil and Environmental Engineering > Utah Water Research Laboratory > Utah State University > 8200 Old Main Hill > Logan, UT 84322-8200 > david.stevens at usu.edu > (435) 797-3229 (office) > > On 4/9/2...

...\frac{k}{n}}{p(k) = k / n}. That is, linear interpolation of the empirical cdf.} \item{Type 5}{\eqn{p(k) = \frac{k - 0.5}{n}}{p(k) = (k - 0.5) / n}. That is a piecewise linear function where the knots are the values midway through the steps of the empirical cdf. This is popular amongst hydrologists.} \item{Type 6}{\eqn{p(k) = \frac{k}{n + 1}}{p(k) = k / (n + 1)}. Thus \eqn{p(k) = \mbox{E}[F(x_{k})]}{p(k) = E[F(x[k])]}. This is used by Minitab and by SPSS.} \item{Type 7}{\eqn{p(k) = \frac{k - 1}{n - 1}}{p(k) = (k - 1) / (n - 1)}. In this case, \eqn{p(k) = \mbox{mode}[F(x_{k})]}{p(k)...

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

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 <-

...(in package reshape) and summary.formula (in package Hmisc). * Renext (1.0-0) IRSN http://crantastic.org/packages/Renext R package dedicated to some Extreme values problems and allowing the use of the so-called &quot;renewal method&quot; which is popular among french-speaking hydrologists. * rgp (0.1-0) Oliver Flasch http://crantastic.org/packages/rgp RGP is a simple modular Genetic Programming (GP) system build in pure R. In addition to general GP tasks, the system supports Symbolic Regression by GP through the familiar R model formula interface. GP individuals are r...