NYGeog

Geography, GIS, Geospatial, NYC, etc.

Thursday, August 4, 2011

Removing or Flattening Z and M values from a point Feature Class

I've had to flatten a Z value-laden point file before, or for whatever reason seen CAD data with M-awareness. For the life of me though I couldn't recall how the heck I did it in the past. It's like those tasks in GIS you do only once in a blue moon and cannot remember the name of the tool or what terms to search (see lattice dem).

Anyway, its actually a very simple process of exporting your data in ArcCatalog and just setting the environments.

http://support.esri.com/en/knowledgebase/techarticles/detail/35818

from Esri:

Summary

Instructions provided describe how to create a copy of a feature class and disable M- and Z-value associations for the output feature class. These associations cannot be removed from an existing feature class.

M-values are routing values.

Z-values are elevation values.

Procedure

  1. Browse to ArcToolbox > Conversion Tools > To Geodatabase.
  2. Open the Feature Class to Geodatabase (multiple) tool.
  3. Add all the feature classes into the Input Feature Class parameter.
  4. Select an Output Geodatabase.
  5. Click the Environments button at the bottom of the tool dialog box.
  6. Expand the General Settings.
  7. For the parameter, Output has Z Values, change the value to Disabled.
  8. For the parameter, Output has M Values, change the value to Disabled.
  9. Click OK in the Environments dialog box.
  10. Click OK to execute the geoprocessing tool.

Esri Press Books I've been reading & Float vs Double

It's been a while since my last post, I've been using twitter more and more, which means I've been posting less and less content and tips and tricks. I've been spending a lot of time messing around with Python (and after a few months of realizing I had the wrong installation of Python, I've now got my arcpy and other modules running smoothly) and relearning how to do things with modelbuilder.

I've started going through Getting to Know ArcGIS: Modelbuilder (http://esripress.esri.com/display/index.cfm?fuseaction=display&websiteID=195&moduleID=0) to help relearn and understand the things I've been doing for a few years. This is the first comprehensive text on modelbuilder I've seen and there is so much value in Iteration and a whole slew of other tools that would have helped my modelbuilder experiences earlier on.

I've also been reading Modeling Our World (2nd Edition): The ESRI Guide to Geodatabase Concepts (http://store.esri.com/esri/showdetl.cfm?SID=2&Product_ID=1247&Category_ID=56). This book is really great. It provides a great overview of GIS data and is a great all-in-one refresher. So I'm going to try and post more and more about the little things in ArcGIS.

Now, on to Float vs. Double.

So for a long time I've been defaulting to using Double because it allows for 16 significant digits. However, as I read in Modeling Our World, Float stores 7 significant digits and is half the storage space of Double. I usually use Double when dealing with decimals but after realizing that I'm essentially expanding all my databases, with sometimes many many fields, to be double (no pun intended) the size they need to be because often when I deal with decimals, 7 digits is more than enough. So by cutting down the size of my databases I will be reducing my storage footprint but also hopefully speeding up my processing time.

DUHHHHH.

So the takeaway should be, if you don't need Double, use Float.

"Floats use half the byte storage of doubles" - Michael Zeller, Modeling Our World

For more info on field types see:
http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//003n0000001m000000.htm

Tuesday, May 10, 2011

My First Google Fusion Map

Below is my first Google Fusion map showing 2000 Census Tract boundaries in NYC. I haven't messed around with Fusion much but will be looking forward to seeing if I can use it for some of my projects.

Monday, May 9, 2011

The future of ArcGIS on Apple Computers (running BootCamp) and using external drives with the faster I/O Thunderbolt

So with the release of the latest Apple Macintosh MacBook Pro and iMac computers with the new Thunderbolt I/O I have been thinking a lot about what this means for running ArcGIS software on Mac hardware. When I'm not in the office I'm running ArcGIS one of three ways on my mac; Remote Desktop Connection, Virtualization (Parallels or VMWare Fusion), OR by using Bootcamp.

Remote Desktop Connection - requires internet connection and my desktop at work to be on; screen space and graphics are lacking, faster b/c it writes directly to internal drives.

Virtualization - I've pretty much given up on this since there's reduced performance from allocation of RAM.

Bootcamp - this is my preferred method of using ArcGIS, however since my disk space is finite I tend to run this on external drives, thereby reducing my processing speed b/c of the read/write time. I use either FAT32 (which stinks b/c of the file size restrictions) or NTSF which supposedly, but I haven't had trouble with it yet, has problems writing when using the Mac OS.


When using Bootcamp, I also write to my Mac's main hard-drive sometimes as well as Mac OSX (Journaled) formatted disks using MacDrive.

Why do I run ArcGIS on a mac? Well mostly b/c I just find the Mac hardware and experience much better. Also, I find that my system is actually more stable. So if I could write to disk using Thunderbolt ports, assuming Bootcamp has the write Drivers and I can use MacDrive to access Mac OSX (Journaled) drives for data, I would most certainly build a very nice reliable primary system using ArcGIS on Apple hardware utilizing Thunderbolt I/O technology.

I look forward to learning if and how I could do this.

Thursday, April 28, 2011

How Much Do GIS Consultants Charge in 2011?

In Directions Magazine Atanas Entchev posted an article entitled How Much Do GIS Consultants Charge in 2011?

Billing rates, summary of all respondents



Billing rates, summary of private entities



Commentary
  • A few interesting (to me, at least) observations:
  • While private entities charge more (as expected), they do not charge that much more than non-profits and academic institutions.
  • The lowest prices in all categories (except data conversion) came from private entities.
  • The survey results jive nicely with the GSA schedules and the New Jersey GIS state contract pricing.
  • The only notable exception is the data conversion numbers – higher on average in the survey than in other data sources.
  • I am surprised that training does not command higher rates.
  • Applying the 25% rate of inflation change to the 2001 prices gets us very close to the numbers in the above tables.
Comments from survey respondents
  • “Tough economy has started fierce price wars.”
  • “Consulting jobs in West Texas are rare. I usually quote by the job.”
  • “I think you should have also asked how many years you have been in business. While I put my hourly rate down, 80% of my business is project-based fees as opposed to hourly.”
  • “I charge different rates on a sliding scale depending on the client; e.g. charge less for non-profits and more for private clients.”
  • “I live in a rural community and realize my rates are very low. I have lower rates when I have on-site services with a set hourly commitment.”
  • “I also work for a flat project fee. My clients are all non-profits, so I tend to think I charge less than say private company contractors.”
  • “I have to spend a lot of 'business development' time to get work. I charge $150 per hour.”
  • “These rates are for our NYC staff, most of our other locations have lower rates.”
  • “Many projects not on hourly basis but fixed price.”
  • “We also charge a flat fee for plotting maps- $35 (does not include labor for setting up map files or data for presentation).”
READ FULL ARTICLE HERE

Tuesday, March 22, 2011

NYTimes: 200th Birthday for the Map That Made New York

200th Birthday for the Map That Made New York
Check out this cool article on the 200th B'day of the grid map, known as the Commissioners' Plan of 1811 (arguably one of the most influential determinants of the Manhattan landscape) that gridded most of Manhattan. And this really cool interactive map feature that allows you to overlay the old historic maps with the current geography and also street openings in Manhattan over time.

In contrast to Pierre L’Enfant’s grandiose national capital, the street commissioners adopted what Reuben Skye Rose-Redwood, a geographer and expert on the grid, described as “a physical representation of the Cartesian coordinate system.”