<div dir="ltr"><div><div><div><div>Joe,<br><br></div>This was fun, thanks for putting it together, I'm looking forward to the next one. <br><div>I have to say that I'm impressed by Aaron's knowledge and level of detail, and it's not the first time.</div><div><br></div></div>I've used Python to parse your hourly dump and visualize it, as well as comparing with the Barrow EPW (converting your hourly dump to SI Units). I've posted that on Github, where you can already look at the code + graphs since it's in a jupyter notebook, but you could also download it and run it on your machine. My hope is that I'll convert one or two members of this list to coding :) <br></div><div>For the record, the actual parsing of the hourly dump into a usable format (pandas.DataFrame) took me about 5 minutes and 16 lines of code (it was a very simple one though).<br><a href="https://github.com/jmarrec/BINM_Challenge/blob/master/Analyse_BINM.ipynb">https://github.com/jmarrec/BINM_Challenge/blob/master/Analyse_BINM.ipynb</a></div><div><br></div>Cheers,<br></div>Julien<br></div><div class="gmail_extra"><br clear="all"><div><div class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div>--<br>Julien Marrec, EBCP, BPI MFBA<br>Owner at <a href="http://www.effibem.com" target="_blank">EffiBEM</a><br>T: +33 6 95 14 42 13<br><span style="color:rgb(0,0,0)"><br></span><span style="color:rgb(0,0,0)">LinkedIn (<a href="https://www.linkedin.com/in/julienmarrec" target="_blank">en</a>)<span style="color:rgb(0,0,0)"> <i>| </i></span>(<a href="https://fr.linkedin.com/in/julienmarrec/fr" target="_blank">fr</a>) : </span><br><span style="color:rgb(0,0,0)"><a href="http://www.linkedin.com/in/julienmarrec" target="_blank"></a></span></div></div></div></div></div></div></div></div>
<br><div class="gmail_quote">2017-12-07 10:40 GMT+01:00 Joe Huang <span dir="ltr"><<a href="mailto:yjhuang@whiteboxtechnologies.com" target="_blank">yjhuang@whiteboxtechnologies.com</a>></span>:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF">
I got a total of five responses, all of which are attached at the
end of this e-mail. Although I was focusing on the FORMAT of the
*.BIN weather file, most of the respondents focused on the data
instead, and to my chagrin more intensely than I have, esp. Julien
who pointed out an anomaly in the direct normal radiation that made
me gasp and go back into my file and processing procedures. Kudos
to Julien for spotting that, but I'll explain what happened there
following his e-mail attached below.<br>
<div class="m_-5901030097413489824moz-forward-container">
<p>The three answers I was seeking are:</p>
<p>(1) <b>The weather file is for a location above the Arctic
Circle</b>, which would make DOE-2.1E crash due to a bug in
the shading calculation but not in DOE-2.2 which fixed this bug
in 2004. The point here is that this is a problem in DOE-2.1E
but NOT in the *.BIN format, except it might seem that way
because the DOE-2 weather packer also crashes because it uses
the same shading routine to generate the weather statistics.</p>
<p>(2) <b>The weather file is for a leap year with the output
file showing Feb. 29th</b>. I've heard many people say that
DOE-2 weather files contain only 365 days, but that's absolutely
not true. The *.BIN format stores data for 12 months of 32 days
each, or 384 days! The reason that Feb. 29th never shows up in
a DOE-2 run is that the developers never bothered to reset the
February day count to 29 on leap years, even though DOE-2
calculates when that's the case. Now that more people are
running DOE-2 with actual historical years, it's well past time
for this little fix to be implemented. <br>
</p>
<p>(3) <b>The weather file reports shows the weather parameters
to an additional decimal of precision</b>, i.e., temperatures
are to the 0.1F, pressures to 0.01 inches of mercury, solar
radiation to 0.1 Btu/sqft, and wind speeds to 0.1 mph. This
required a modest change to the BIN format that I implemented as
the *.BINM (M for Modified) starting in 2011. This leads to
what I think is the most fascinating part about the DOE-2 *.BIN
format that was developed in the early 1980's when computer
memory was very limited. Members of the original development
team (Ender Erdem and maybe Fred Buhl) came up with the strategy
of "packing" the data by converting all data to integers, pack
four integers into one big integer, and then store them in the
file in binary form. By so doing the *.BIN files are only 146K
(70-80KB zipped), whereas other formats can be well over 1MB
(200+KB zipped). DOE-2 also uses the *.BIN format to improve
execution speed by not reading the data an hour at a time or
8760 ASCII reads, but by reading 16 day chunks at a time or 24
binary reads for the entire year (which also explains why the
*.BIN format contains 24x16 or 384 days). <br>
</p>
<p>So now let's look at how did our contestants do, listed in
order of when I received their answers:<br>
</p>
<p>Parag - 0 out of 3 (he looked almost entirely on the data,
not on the format)</p>
<p>Julien - 1 out of 3 (he noticed the leap day, but also focused
his attention on the data and pointed out two problems that I
will address following his e-mail below)</p>
<p>Aaron - 2 out of 3 (I was impressed that he knew about the
packing and unpacking process, but did not notice the leap year)</p>
<p>Javed - 0 out of 3 (but had a good question on why DNI (Direct
Normal) is larger than GHI (Global Horizontal) that I will
answer following his e-mail below)</p>
<p>Nathan - 1 out of 3 (he also noticed the leap day, and had
other questions that I will answer following his e-mail below).</p>
<p>So, nobody noticed all three answers, but since it's the
holiday season, I will make them all winners and provide a
historical year weather file of their choosing. Just e-mail me
if you're interested and tell me which one you want.</p>
<p>This has been an interesting and insightful experience for me.
I hope others also found it entertaining and useful, as well.
I've learned that (1) think twice before coming out with a
flawed contest rule, (2) look over more times whatever I put out
on the Web.</p>
<p>(please be sure to read the contestant's submittals and my
responses below)<br>
</p>
<p>Joe</p>
<pre class="m_-5901030097413489824moz-signature" cols="90">Joe Huang
White Box Technologies, Inc.
346 Rheem Blvd., Suite 205A
Moraga CA 94556
<a class="m_-5901030097413489824moz-txt-link-abbreviated" href="mailto:yjhuang@whiteboxtechnologies.com" target="_blank">yjhuang@whiteboxtechnologies.<wbr>com</a>
<a class="m_-5901030097413489824moz-txt-link-freetext" href="http://weather.whiteboxtechnologies.com" target="_blank">http://weather.<wbr>whiteboxtechnologies.com</a> for simulation-ready weather data
(o) (925)388-0265
(c) (510)928-2683
"building energy simulations at your fingertips"</pre>
<p>Attached e-mails follow in the same order (only final e-mails
shown)
------------------------------<wbr>-----------------------------</p>
<div class="m_-5901030097413489824moz-cite-prefix">On 12/5/2017 11:24 PM, Parag Rastogi
wrote:<br>
</div>
<blockquote type="cite">
<pre>Hi Joe,
Don't know anything about the DOE-2 platform, but here's my take on the meteorological "oddities". Thanks for organising this challenge - it's really cool!
1. A large part of the year has zero sun while the other part has sun for 24 hours.
2. The humidity is _really_ high - the WBT and DBT are mostly within a degree of each other. Don’t know if DOE-2 has a problem with that?
3. In the summer months, the direct normal is sometimes larger than global solar. That is really odd!
4. I would not live here - Glasgow winters are bad enough.
Parag</pre>
</blockquote>
YJH answer: Yes, I picked Barrow on purpose to show that the
*.BIN format still works for places above the Arctic Circle or
below the Antarctic Circle. RH is generally very high in frigid
climates because the cold air cannot hold much moisture (that's
why there's always frost in your refrigerators!). The DNI can
often be greater than the GHI at low sun angles, since the DNI is
calculated normal to the sun, while the GHI is calculated for a
flat horizontal plane. Yes, stay in Glasgow or at least don't go
to Barrow in place of Glasgow.<br>
<br>
On 12/6/2017 6:35 AM, Julien Marrec wrote:<br>
<blockquote type="cite">
<div dir="ltr">
<div>
<div>
<div>
<div>
<div>Hi Joe,</div>
<div><br>
</div>
<div>Replying off the mailing list, since it would
kinda beat the point of "first 5 to find the error"
otherwise.<br>
</div>
<div><br>
</div>
<div>1. There is a 29th of February, but 1912 was
indeed a leap year, so I'm not sure whether that
qualifies for a bug (can't remember how eQuest/DOE
deal with leap year weather files).</div>
<div><br>
</div>
<div>2. There is an unsual peak of Global Solar
radiation mid November (11 to 18th) while the Direct
Normal stays at zero. The peak has values at 400
BTU-HR/SQFT while the max is 250 for the rest of the
year. 400 means 1250 Wh/m2, which is just short of
what the Extraterrestrial Direct Normal Solar
Radiation is.<br>
</div>
<div><br>
</div>
<div>In IP units:<br>
</div>
<div><img src="cid:part3.6441A793.783D7ADC@whiteboxtechnologies.com" alt="Images intégrées 1" style="margin-right:0px"><br>
</div>
<div><br>
</div>
<br>
</div>
I don't see any problem with the Atmospheric pressure,
not the relative humidity I computed with Db, Wb and
Atm. Wetbulb and drybulb are where I expect them for
this location (checked against the EPW file for the same
location too).<br>
</div>
<div><br>
</div>
<div>So I'm not sure what's the 3rd problem, I'd say that
it's probably not a good idea to live there unless you <b>really</b>
like cold weather?<br>
</div>
<br>
</div>
Best,<br>
</div>
Julien<br>
</div>
<div class="gmail_extra">--<br>
<div>
<div class="m_-5901030097413489824gmail_signature" data-smartmail="gmail_signature">
<div dir="ltr">
<div>
<div dir="ltr">
<div>
<div dir="ltr">
<div>Julien Marrec, EBCP, BPI MFBA<br>
Owner at <a href="http://www.effibem.com" target="_blank">EffiBEM</a><br>
T: <a href="tel:06%2095%2014%2042%2013" value="+33695144213" target="_blank">+33 6 95 14 42 13</a><br>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</blockquote>
YJH answer: I was embarrassed that you noticed the input echo has
1912 instead of 2012, which was because DOE-2.1E was not Y2K
compliant, so I had to set the year to 1912 in order for DOE-2.1E
to run. I was further more astonished to see the wierd spike of
GHI in November, which wasn't there in the actual weather file
(see below). <br>
<img src="cid:part5.EB27FE6E.01A01089@whiteboxtechnologies.com" alt=""><img src="cid:part6.383BF05F.5EF03419@whiteboxtechnologies.com" alt=""><br>
<br>
Since DOE-2.1E can't run with this weather file, I used a version
that I modified that took care of the high latitude problem as
well as adding the extra precision. When I checked the Fortran
source code, I found this extra line (<<<) that I have
no memory of ever inserting nor why I did so (sound like a
politician, don't I ? :-) ). <br>
DO 500 I=1,14<br>
CALC(I) = FLOAT(IWTH(I))*XMASK(I,2) + XMASK(I,1)<br>
IF (I.LE.2) CALC(I)=CALC(I)+IWTH2(I)/10.<br>
IF (I.EQ.11.OR.I.EQ.12) CALC(I)=CALC(I)+IWTH2(I-8)/10.<wbr>
<<< ???<br>
500 CONTINUE<br>
So, if you believe my story, this spike in GHI was the result of
my unpacking routine and not in the weather file itself. A
curious thing with the solar in such Arctic locations is that the
GHI is above 0 for all hours over two months (see central bottom
of the left plot), indicating the proverbial midnight sun during
the summer.<br>
<br>
<br>
<div class="m_-5901030097413489824moz-cite-prefix">On 12/6/2017 9:05 AM, Aaron Powers
wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">Hey Joe,
<div><br>
</div>
<div>Here's what I could find. It's really 2 things since the
first 2 and last 2 are related.</div>
<div><br>
</div>
<div>1. Normal DOE2 binary weather files are made up of 24
records of 6208 bytes each. So each file is roughly 145
kB. Your file is 182 kB, so each of the 24 records is 7744
bytes in length. I'm not sure what you have in the extra
bytes, but the first 6208 bytes of each record is exactly as
you would expect in a DOE2 packed file. So I am able to
read the .bin file by just ignoring the bytes after 6208 of
each record.</div>
<div><br>
</div>
<div>2. You have more precision for each data point. I'm
guessing this must be tied up to the extra bytes in each
record. For example, the drybulb, wetbulb, and pressure are
usually packed into a single integer value. The first and
last 4 bits of the integer are junk due to the way Fortran
writes binary data. The atmospheric pressure takes up 15
bits and the drybulb and wetbulb take up 8 bits each. After
encryption, this allows the drybulb and wetbulb to be stored
with 0 decimal places and the pressure with 1 decimal
place. Similarly, the direct normal and global horizontal
are usually stored with 0 decimal places. Your output file
shows a higher precision for each of these data points.
Again, I'm guessing that this extra precision is in the
extra bytes in each record.</div>
<div><br>
</div>
<div>3. Since Barrow is above the Arctic Circle, it gets the
midnight sun and polar night. </div>
<div><br>
</div>
<div>4. Related to previous, in the peak of summer, radiation
has very little diffuse component and during winter is
almost all diffuse (when it exists).</div>
<div><br>
</div>
<div>Aaron</div>
</div>
</blockquote>
YJH answer: You're completely correct in all your suppositions,
Sherlock Holmes ! What I've done is to add another array of 384,
each containing the extra precision for the two temperatures,
pressure, wind speed, and the two solar irradiances. It was my
former colleague at LBNL Ender Erdem who assured me that in a
binary read, this extra integer would be ignored, thereby
guaranteeing compatibility between the *.BIN and *.BINM formats.
However, once the extra read is added, there has to be a flag
telling DOE-2 NOT to do that for the older *.BIN format. That's
the main reason why I haven't pushed very hard on this.<br>
<br>
<div class="m_-5901030097413489824moz-cite-prefix">On 12/6/2017 9:18 AM, Javed Iqbal
wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">
<div class="gmail_default"><font face="arial, helvetica,
sans-serif" color="#000000">Dear Sir Joe,</font></div>
<div class="gmail_default"><font face="arial, helvetica,
sans-serif" color="#000000"><br>
</font></div>
<div class="gmail_default"><font face="arial, helvetica,
sans-serif" color="#000000">I am able to find something
though NOT all which looks to me unusual and hence
reporting here.</font></div>
<div class="gmail_default"><font face="arial, helvetica,
sans-serif" color="#000000"><br>
</font></div>
<div class="gmail_default"><font face="arial, helvetica,
sans-serif" color="#000000">1) The following screenshot
for <b><u>22nd April</u></b> shows that Direct Normal is
greater than the Global solar. As per my limited knowledge
in this direction, usually Direct Normal Solar can be
greater than Global solar (Direct+diffuse) or GHI during
certain periods such as morning or afternoon hours.
Whereas, the hourly report shows Direct Normal Solar is
always higher (~8-10 times) than the Global Solar. If this
is one of the acceptable discrepancy than there are many
such instances could be found in in the hourly weather
file. </font></div>
<div class="gmail_default"><font face="arial, helvetica,
sans-serif" color="#000000"><br>
</font></div>
<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;color:rgb(7,55,99)"><img src="cid:part7.DCB51E63.51D94FAF@whiteboxtechnologies.com" alt="Inline image 1" height="515" width="407"><br>
</div>
<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;color:rgb(7,55,99)"><br>
</div>
<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;color:rgb(7,55,99)">Let
me know your thought on this.</div>
<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;color:rgb(7,55,99)"><br>
</div>
<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;color:rgb(7,55,99)">Sorry
I could do this much only out of my busy schedule.</div>
<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;color:rgb(7,55,99)"><br>
</div>
<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;color:rgb(7,55,99)">Thanks,</div>
</div>
</blockquote>
YJH answer: The DNI can be larger than the GHI frequently in the
Arctic locations because of persistently low sun angles. However,
the numbers that you've highlighted above have DNI/GHI ratios that
do seem excessive. All these solar irradiances are calculated
using several empirical and analytical models and so could always
be wrong. However, the formulation of the direct solar model
calculates the DNI as a sigmoid function of the ratio between the
GHI and the extraterrestrial global horizontal radiation, so it
would seem difficult to produce a DNI that would violate physical
reality, i.e., GHI = DNI*sin(solarZ) + DHI. Time permitting, I
may look more into this.<br>
<br>
<div class="m_-5901030097413489824moz-cite-prefix">On 12/6/2017 2:01 PM, Nathan Brown
wrote:<br>
</div>
<blockquote type="cite">
<div>Ok, so here’s my revised list:</div>
<div><br>
</div>
<div>1. Hour index is 1, not zero (not different from
.epw, but still annoying to deal with while post processing)<br>
2. Solar noon is not aligned to the noon timestamp. Does this
mean permanent DST?<br>
3. This file contains data for 2/29<br>
<div><br>
</div>
<div><br>
<div>
<div style="margin:0px;font-family:Arial,Helvetica,sans-serif;font-size:11px;color:rgb(128,128,128)">
<div> <span style="color:rgb(199,96,30)">Nathan Brown, BEMP, LEED AP</span> ~
Associate </div>
<div style="font-size:13px;color:rgb(133,149,131);font-weight:bold"> LOISOS <span style="font-weight:normal">+</span> UBBELOHDE </div>
<div style="color:rgb(204,204,204)"> - - - - -
- - - - - - - - - - - - - - - - - - - - - - </div>
<a href="http://www.coolshadow.com/" target="_blank"><span style="color:rgb(162,171,158)">www.coolshadow.com</span></a><br>
</div>
</div>
<br>
</div>
</div>
</blockquote>
YJH answer: 1 is not a correct answer since, as you note, the
convention is the same for both *.BIN and *.BINM, as well as
*.epw files. The annoyance you feel msy be due to the mixed use
of cardinal and ordinal numbers in the weather files. The
standard convention on simulation weather files is the formal,
i.e., Hour 1, Hour 2, etc., whereas the convention on weather
station reports is the latter, Hour 00:00, Hour 01:00, etc. In my
opinion there is an inconsistency on simulation weather files
where most of the measurements (temperatures, etc.) are reported
by the timestamp, i.e., 00:00, but incorporated as Hour 1, etc.,
while others, notably solar and rainfall, are both measured and
reported cardinally as Hour 1, etc. I'll talk more about this in
the next contest on the epw file format.<br>
<br>
How are you deducing that solar noon is not aligned to the noon
timestamp? As for DST, I feel that weather files should NEVER
incorporate any such human-made artifacts. There are several
factors you should consider when comparing solar noon to local
standard noon: (1) difference in longitude between the standard
meridian and the location (Barrow); in this case, they are 150.00
West and 156.782 West respectively, or a 27 minute effect, (2)
the solar irradiance is given over the past hour, so the average
solar position for Hour 12 is at 11:30 AM local time rather than
12:00 PM, another 30 minute effect, and (3) "Equation of time"
that makes local time faster or slower than solar time by +- 15
minutes at the most. I don't know if these effects combined
accounts for the difference between solar and local noon that you
see.<br>
<br>
<br>
</div>
</div>
</blockquote></div><br></div>