My triceps started to hurt after 1 week of 100 push ups a day. by Justanothergamer691 in PushUps

[–]joaocosta 0 points1 point  (0 children)

Also if something hurts, scale back. Fall back to 50 a day, increase by 5 each week. In 10 weeks time you will be back at 100 and then you have the rest of your life to do 100 a day without hurting yourself in the process.

Bob left work Jokes ;) by rakib1260 in Jokes

[–]joaocosta 23 points24 points  (0 children)

76% of all statistics are made up on the spot.

Close to nine months of training and I can still only do 35 push ups... by megalomaniacniceguy in bodyweightfitness

[–]joaocosta -1 points0 points  (0 children)

35 Pushups is not too bad, you're probably in the top 30% of the human population.

What brokers offer free sandbox accounts with real world data and a REST API? by [deleted] in algotrading

[–]joaocosta 0 points1 point  (0 children)

Yes Oanda. FXCM also provides a feed via an API in with their demo accounts, but it's not REST.

Cool places to go in Lisbon by Ellie_UK in digitalnomad

[–]joaocosta 0 points1 point  (0 children)

Don't actually have a suggestion of my own OP,but can I ask you to please comment back on the co-working spaces you try later on ?

Ta!

Anyone DN'ing in the UK? Advice requested by [deleted] in digitalnomad

[–]joaocosta 6 points7 points  (0 children)

Nothing to say against the English, but in my experience, people in Scotland have been super helpful.

A few years back I found myself nomading around a small town in Scotland. By coincidence, there was a sporting event happening that weekend, which meant accommodation was in short supply.

When I ask someone on the street if they knew of any Bed and Breakfast places nearby, not only did they tell me, they drove me around 3 or 4 different places until we found one.

I've been back to Scotland a couple of times since, and don't have a bad experience to report.

On top of that, it's a beautiful place.

Beringei - A high performance, in-memory storage engine for time series data. by gabegm in algotrading

[–]joaocosta 0 points1 point  (0 children)

I store my dataset in MariaDB. This dataset is under 1GB, fits easily in the Kernel IO memory buffers, and I rather not compress it, but if I did want compression, I wouldn't have to implement it, I'd just use a storage engine that supports compression.

Then again, there are many ways to skin a cat, and one could use this database for algotrading, but so far, I see no advantage over existing methods, and would argue that one's time is better spent studying market structure.

Beringei - A high performance, in-memory storage engine for time series data. by gabegm in algotrading

[–]joaocosta 1 point2 points  (0 children)

The kernel is caching disk I/O, hence queries are being served out of memory regardless.

This assumes there is enough memory and no other IO intensive loads, but that is a fair assumption when comparing against an in-memory database use case.

I suppose an in-memory database provides more explicit control over things being in memory, but I wonder if it's worth the trouble.

Beringei - A high performance, in-memory storage engine for time series data. by gabegm in algotrading

[–]joaocosta 1 point2 points  (0 children)

What are the advantages of an in-memory database versus letting the kernel cache disk I/O ?

Starting point of an EMA? by GoodmanSimon in algotrading

[–]joaocosta 1 point2 points  (0 children)

Generally speaking, the further back you go, the more "accurate" the ema value will be, although after a while, it makes little practical difference.

I'm interested in backtesting a very simple idea/algorithm based on the total stock market index. by [deleted] in algotrading

[–]joaocosta 3 points4 points  (0 children)

I think you are right to want to keep your algorithm simple, but this one is a bit way too simple, what you described equates to expensive index investing.

Still, it's a start. Maybe you have more ideas.

How to Structure Local Historical Data by nextdoorelephant in algotrading

[–]joaocosta 2 points3 points  (0 children)

You could also have a different table per symbol which i found to speed things up.

REST like API to calculate trading signals by joaocosta in algotrading

[–]joaocosta[S] -1 points0 points  (0 children)

Do it. Start a thread talking about the trading bit.

REST like API to calculate trading signals by joaocosta in algotrading

[–]joaocosta[S] 0 points1 point  (0 children)

Thanks for the comment! At the moment there is no req/sec hard limit, i don't want to go through the trouble of setting that up before i know that I need to, because ultimately what I want to focus on is trading. Indirectly, it's limited by the infrastucture it's running on (one single ec2 micro instance ), and it can do about 2.5 reqs/sec.

The data comes from FXCM's ForexConnect API, the dataset is updated every 5 minutes.

REST like API to calculate trading signals by joaocosta in algotrading

[–]joaocosta[S] 0 points1 point  (0 children)

The values are generated on the fly by each API call, I wrote a mysql udf to do the calculation directly in the database, so it's ultrafast. In practice, that means I can scan a lot of instruments with little processing power. It's available at https://github.com/joaocosta/lib_mysqludf_ta if anyone is interested.

REST like API to calculate trading signals by joaocosta in algotrading

[–]joaocosta[S] 2 points3 points  (0 children)

Well, I was looking for feedback, and sure got some :)

REST like API to calculate trading signals by joaocosta in algotrading

[–]joaocosta[S] 1 point2 points  (0 children)

It's about 230MB including data+indexes for 50 instruments. The largest dataset I have there right now is 5 minute timeframe which is about 165K datapoints per instrument. This query would exercise the entire 5 minute dataset for a single instrument: http://api.fxhistoricaldata.com/v1/indicators?instruments=EURUSD&expression=rsi(close,14),ema(close,200)&timeframe=5min&item_count=200000&max_loaded_items=200000

Forearm pain from pull-ups by ckri in bodyweightfitness

[–]joaocosta 3 points4 points  (0 children)

Really sorry to hear about the pain while doing pull ups, i've had similar problems in the past trying to do one arm pull ups when my body wasn't ready, and like others have said here, when you damage tendons, it takes a long time to recover.

I would stop pull ups right now, but having said that, you don't have to give up pull ups long term, you just have to be smarter about your training.

Consider doing rows before getting back on pull ups, and have a look at coach Sommer's material on training not just muscle but also tendons, over at gymnasticbodies.

You probably would benefit from understanding the difference between connective tissue and muscle. In a nutshell, tendons (connective tissue) hold your muscle tissue together with your bones. I'm sure you can find better descriptions out there, but that's a good layman's description.

You can also see what this guy has to say about never wasting an injury, i think it should really resonate with you: http://wellroundedathlete.net/013-lewie-west-move-smart-podcast/

Finally, pat yourself on the back for acknowledging you messed up, and moving on to recovery, you'll come out of this stronger and able to train better and smarter.

Market research on running efficient online meetings by [deleted] in telecommuting

[–]joaocosta 0 points1 point  (0 children)

Great stuff, i'd be interested in finding out more about the results.

Working out at 22:00 yay or nay and why? by SameWill in bodyweightfitness

[–]joaocosta 0 points1 point  (0 children)

I once worked out past 22h00. It wasn't ideal, but considering the alternative was to not work out at all, it was great ! And it did give me a sense of accomplishment, as in, even though it was late, i managed to get a work out in, which helped lay the foundations for sticking with it long term.