freedom | Source files for SiFive 's Freedom platforms

You can use the relevel() function to specify which level of the factor is the reference level. Assuming the variable Grupo is already a factor, this should work:

I'll give my two cents, without being 100% sure that what I am about to say is correct. Joe Duffy is a world-class expert in multithreading, but I think that in this implementation he has been overly cautious regarding the cross-thread visibility of the internal state of the LockFreeStack class. The volatility of the Node.m_next field is redundant in my opinion. The Node instances are mutable, but they are only mutated before they are linked in the internal linked list. After that phase they are practically immutable. That mutable phase is performed by a single thread, so there is no chance that another thread may see a stale version of a Node instance.

That leaves only the possibility of instructions re-ordering, as a reason for declaring the Node.m_next as volatile. Since the n.m_next = h; assignement is sandwiched between reading another volatile field (m_head), and an Interlocked.CompareExchange operation, I would assume that a possible re-ordering of the instructions that would compromise the correctness of the implementation is already prevented, but as I said I am not 100% sure.

I am pretty sure though that the implementation of the LockFreeStack class could be improved performance-wise, at the cost of becoming slightly more allocatey, by making immutable the Node class. Nowadays (C# 9) this can be achieved simply by switching from type class to type record. This is how such an implementation would look like:

You can add it into set so that there wont be any duplicates and remove comma if not required :

You can add width to .dates itself and change its display property because width won't wrok for inline elements. I moved the character '-' outside so it looks nicer. You can also wrap this in and give some margin to make space so it looks even more nicer.

I think IsControllable() is doing the right thing. If you have a single body with a floating base, then you have 13 state variables (7 positions, 6 velocities). If you were to simply linearize the equations, then you are right that the resulting linear system would not know about the unit quaternion constraint. Asking for controllability of this system would be asking you to drive the system to the origin (quaternion => 0 ~= unit quaternion). Since your dynamics model cannot achieve that, even in the linearization, I expect your system is not controllable in that linearization.

You could replace the quaternion floating base with a roll-pitch-yaw floating base. We have some API that will make that easier coming in https://github.com/RobotLocomotion/drake/issues/14949 . But in the mean time, you can add the three translations and a BallRpyJoint.

The alternative to look into the literature on control in SE(3) directly using quaternions. There are elegant results there, but linear analysis won’t help.

OK, solved (with the help of Microsoft support who sent a screenshot of the method being invoked on their side).

It seems that the method is not to be invoked from management.azure.com like all the other methods. Nope. It has to be invoked from the Management API URL that can be found in the Management API section of your APIM in Azure.

Curiously, the management API toggle does not even have to be on.

Your GET request should be like this:

https://my_apim_instance.management.azure-api.net/subscriptions/my_subscription_id/resourceGroups/my_resource_group/providers/Microsoft.ApiManagement/service/my_apim_instance/identity?api-version=2019-12-01

Now cue in the ever-helpful posters with ever-useful post-solution advice.

This seems like a very unusual way to write an R function, but you could do

You are on the right track. This is how it can be done

Some useful information for such questions in R/exams:

• The extol can also be a vector so that you can set different tolerances for coefficients and R-squared etc.

• When asking about the R-squared, though, I typically ask for it "in percent". Then the same tolerance may be suitable as for the coefficients.

• I would recommend to control the size of the coefficients suitably so that digits and extol can be set accordingly.

• Personally, I typically store the exsolution at a higher precision than I request from the students. For example, exsolution could be 12.345678 while I only set extol to 0.01. This makes sure that when the correct answer is rounded to two decimal places it is inside the correct interval determined by exsolution and extol.

Details on formatting of the coefficients in the summary:

• It is not obvious where exactly the formatting happens: The summary() method for lm objects returns an object of class summary.lm which has its own print() method which in turn calls printCoefmat(). The latter is the function that does the actual formatting.

• When setting the digits in these functions, this controls the number of significant digits and not the number of decimal places. This is particularly important when the coefficients become relatively large (say, in the thousands or more).

• The coefficients are not formatted individually but jointly with the corresponding standard errors. The details depend on the digits, the size of both coefficients and standard errors, and whether any coefficients are aliased or exactly zero etc.

• Without aliased/zero coefficients the formatting from summary(m0) can be replicated using format_coef(m0) as defined below. That's essentially the boiled-down code from printCoefmat().