Calculating complex cos curves from data

[brandy]

Homework Statement

i have to create a mathematical forumal from data of high and low tide depths and times. from that predict the next weeks outcome.
it has to have sin or cos in the equation. a*COS (bx+c)+d or sin.

this is the data given
Mon 09/03/2009 Tue 10/03/2009 Wed 11/03/2009 Thu 12/03/2009 Fri 13/03/2009
TIDE TIME HEIGHT TIDE TIME HEIGHT TIDE TIME HEIGHT TIDE TIME HEIGHT TIDE TIME HEIGHT
Low 12:22am 0.22m Low 1:09am 0.16m Low 1:54am 0.15m Low 2:36am 0.2m Low 3:18am 0.3m
High 6:50am 1.98m High 7:32am 1.99m High 8:11am 1.95m High 8:47am 1.85m High 9:22am 1.72m
Low 1:17pm 0.29m Low 1:54pm 0.22m Low 2:29pm 0.19m Low 3:01pm 0.2m Low 3:32pm 0.23m
High 7:10pm 1.56m High 7:53pm 1.66m High 8:34pm 1.74m High 9:14pm 1.77m High 9:53pm 1.76m

i was thinking of adding 2 different a*COS (bx+c)+d together as it seems to have two main curves going with it. therers the more obvious one and then a subtle one which makes the amplitudes of waves bigger. so i thought i could find information on full moons, new moons, solar eclipses, etc and use that to caluclate a formula.

but i have no idea

i think other people are using a function on their calculator to create it
but i have no idea what.

hellp!


im not asking for you to work it out, the data is pretty hard to read in this format. I am just asking for a method! or a websites or program that can calculate it.
anything. I am so desperate.
PLEEEEEAAAAAASSSSSEEEE

 

[LowlyPion]

Intuitively you know that the fullness of the moon will correlate in some way with the maximum of the tides. Where you are in the cycle and the number of degrees of off set, you will need to fiddle with to determine.

As to heights I suspect that a coefficient off of that with the same period will be able to say something about the heights of your tides as well as the timing.

 

[nlightner]

I understand your frustration and desire to find a method or tool to help you calculate the complex cos curves from your data. One approach you could take is to use a mathematical software such as MATLAB or Mathematica to fit a curve to your data. These programs have functions specifically designed for curve fitting and can help you find the best fit for your data. You can also try searching for online tools or calculators that can perform curve fitting based on your data.

Another approach is to use trigonometric identities and equations to create a formula that fits your data. This may require some knowledge of trigonometry and calculus, but it can be a rewarding and educational experience. You can also consult textbooks or online resources for guidance on how to create such a formula.

In terms of finding information on full moons, new moons, and solar eclipses, you can try looking at astronomical data and incorporating it into your formula. However, keep in mind that these events may not have a significant impact on your tide data, so it may be best to focus on the main curves you have identified in your data.

In conclusion, there are various methods and tools available to help you calculate complex cos curves from your data. It may require some trial and error and a combination of approaches, but with determination and perseverance, you will be able to find a suitable formula for predicting tide outcomes.