How to cut a file in half with DuckDB, and also how to split by date?
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One of the nicest features of DuckDB is that you don’t need to import a CSV before working with it. For example, if your file is called large.csv: View the…
How to combine separate date and time columns into a single date-time column them filter by ID column = C then create Pivot table of events from Event column (where ID column = C) with horizontal access as hourly.
You can do all of that cleanly in DuckDB using one SQL pipeline: combine date+time → filter by ID → build hourly pivot. I’ll assume your CSV has columns like:…
Key methods of extracting limited data sets from single very large file in DuckDB
Keep only the first 100,000 rows and save them COPY ( SELECT * FROM ‘large.csv’ LIMIT 100000 ) TO ‘small.csv’ (HEADER, DELIMITER ‘,’); Extract a range of rows (e.g. rows…
How to select rows based on contents of cells in Excel during analysis of PicoMuon stand-alone data
In Excel, you typically do this with either IF, IFS, or lookup functions depending on what you mean by “select based on content”. Here are the most common patterns: 1)…
LBE-1420 GPSDO locked clock source : Leo Bodnar Electronics
This is an example of a clock source which can be used with SDRs that will accept external clocks for e.g. pulsar observations – the recommendation was made by a…
What is Kalman filter for radio dish feedback?
A Kalman filter is a mathematical method used to estimate the true position and motion of a system when the measurements are noisy. For a radio dish, it can make…
Comparing the Airspy Mini SDR with the RTL-SDR and equivalents for hydrogen line radio astronomy
The Airspy Mini has a maximum IQ sample rate of 6 MSPS, giving a maximum instantaneous bandwidth of approximately 6 MHz. However, there are a few subtleties: Available sample rates:…
Is there any 100wh power bank with excellent reviews?
Yes — there are a few very well-reviewed ~100Wh (airline-safe) power banks, but they are almost all from established brands (Anker, Nitecore, Ugreen). The key point is: anything near 100Wh…
What are the specifications of the Lidl Ultimate UPK 10 H5 power bank? In particular, what is its mAh rating, mWh rating, and what current can it produce at 5V and 12V?
The Lidl Ultimate Speed UPK 10 H5 (also sold as a jump starter / power bank / compressor unit) has fairly well-documented specs. Here are the key values you asked…
How do I convert power bank’s mAh rating into mWh?
To convert a power bank from mAh to mWh, you need to know the voltage (V) of the battery. Key formula mWh = mAh × V Why this works mAh…